There are a handful of unforgettable moments that are seared forever into the minds of boxing fans.

There is a discombobulated Mike Tyson on all fours grasping for his mouthpiece and trying to shove it back in before he is counted out in his monumental upset loss to Buster Douglas.

There is Sugar Ray Leonard pouring it on and finishing Thomas Hearns, who is draped along the ropes in the 14th round of their magnificent first fight.

There is 45-year-old George Foreman landing the shortest right hand you've ever seen to knock out Michael Moorer in the 10th round to regain the heavyweight championship almost 20 years to the day after he lost it to Muhammad Ali.

And then there's heavyweight world titlist Deontay Wilder flattening lineal champion Tyson Fury with a massive right hand-left hook combination early in the 12th round, leaving Fury motionless on the canvas, seemingly knocked into another dimension -- until, amazingly, he beats the count and finishes the fight.

It was Dec. 1, 2018, and a worldwide audience had already seen an excellent fight. Fury had outboxed Wilder for long stretches, but Wilder, the sport's most devastating puncher -- and perhaps the best puncher of all time -- knocked Fury down in the ninth round. Then he seemingly knocked Fury out in the final round before Fury miraculously rose from the mat. Once the bell rang at the end of the 12th, judges ruled it a controversial split draw: 114-112 for Fury, 115-111 Wilder and 113-113.

Wilder (42-0-1, 41 KOs), 34, of Tuscaloosa, Alabama, and Fury (29-0-1, 20 KOs), 31, of England, who have each won two fights since their previous encounter, will meet again Saturday (ESPN+ PPV, 9 p.m. ET) at the MGM Grand Garden Arena in Las Vegas in what is easily the biggest fight of the 2020 schedule so far.

Told to ESPN by those involved, this is the story of the moment that made this fight possible: the unforgettable 12th round of Wilder-Fury I.

Editor's note: Responses have been edited for clarity.

Jay Deas, Wilder's co-trainer and cutman: I think it was one of those historic rounds. It was one of those -- Riddick Bowe-Evander Holyfield I, Round 10; Micky Ward-Arturo Gatti I, Round 9. It was an ebb-and-flow kind of a thing on a heavyweight scale. It had that remarkable moment where the impossible somehow became possible, for Fury to get up when no one thought that that was possible, including me.

Going into the 12th round, each side had a different view of how the fight was going.

Deas: I thought Deontay got off to a lead in the fight. Fury had closed the gap. Deontay scored the knockdown in the ninth to take us a little bit ahead. Fury came back in 10th and 11th. Going into the 12th, I said to Deontay in the corner, "It's a close fight. Can you give me a big finish?"

Shelly Finkel, Wilder's co-manager: Going into the 12th round, I thought it was close, with an edge to Fury, and I felt the knockdown in the 12th made it a draw, and that it was fair.

Jack Reiss, the referee: I thought it was an extremely close fight, and I didn't know who was winning. I knew it was close.

Wilder: We didn't feel we were behind at all. We did feel it was close, either my way or tied. So we were just getting set for a big finish like I always do.

Ben Davison, Fury's former trainer: I told Fury, "You're winning the fight." I told him, "Don't take no silly risks," and going into the 12th, I said, "You're moving your head a little bit too much. I want you to just nullify him, basically. Nullify him this round, see the round out, and you've completed it." There was no way he wasn't winning the fight. Just stay on your feet, and you've won the fight. And he comes out, and he started boxing. Landed a good one-two. But I was always very wary, and I've always been wary of Wilder when he's on the back foot. He springs into his attacks very well, very fast. And Tyson started pushing the fight toward Wilder, and throughout the fight I'd actually said to Tyson, "Look, don't let him lure you in. I know you can see it." And then Tyson got lured in.

Thirty-five seconds into the round, Fury landed a right hand in the center of the ring, and Wilder responded. He missed with a jab but then landed a dynamite two-punch combination: a massive right hand to the side of the head followed by a clean left hook on Fury's chin that floored him. Fury was motionless. Wilder made a throat slash gesture and shimmied his shoulders while Fury was flat on his back with his right knee bent in the air.

Fury: I remember going out for Round 12, going to put on a show in Round 12. I had a mission to knock him out, and I just got caught by a big punch and got knocked down.

Wilder: The combination in the 12th round, that was maybe 90% of my power.

Davison: Wilder couldn't have chosen a better point in the fight to land that shot, when Tyson was fatigued. Tyson still got up and managed to do what he did. That obviously goes beyond the conditioning involved -- but also mental strength.

Deas: Deontay always had an uncanny ability to deliver big, especially when asked. I expected that it would be that kind of a round and that he could make something dramatic happen. When he landed the right hand, I saw Fury start to teeter, start to fall. I knew it was a great shot. I knew Fury had gotten a little bit squared up, but I knew it was a great shot. Then the left hook came out of nowhere. It almost righted the ship. He was going over to the right, and then all of a sudden the left hook leveled him off, and he landed basically flat on his back.

Davison: Wilder is phenomenally heavy-handed. It's his right hand that puts people over, but I think his left hand is still extremely, extremely heavy-handed.

Wilder: I was more impressed than anything, just to see for a second looking over his body and seeing his eyes going to the back of his head, the veins pulsing out of his neck and the way his body was lying on the canvas. It was very impressive. Even more impressive was because Fury said after the fight that his lights just went out, and he didn't even know how he got on the ground or how he got up. To go through all of that or not even know that you're doing it, it's like a zombie or something. But it was entertaining and made the hype for the rematch that much greater because the first fight was controversial.

Finkel: I thought Deontay knocked him out. I got up, and I went to go up the steps because I thought it was over, but Fury got up, and the ref let it continue.

Fury: I wasn't hurt. I didn't feel anything.

Davison: I thought that the fight was over. Usually when a fighter goes down and they're going to get back up, there's some part of their body that's still moving, whether their hands are moving, their feet are moving, they lift their head up. He was just still.

Wilder: I blew a kiss at my wife, too, so, yes, I definitely thought it was over, for sure, just from what I saw with those split seconds of the head hitting in the canvas, which is a dangerous thing. That's scary. That's a scary moment for a person, and that's why boxing is so dangerous, man.

Deas: I'm not the kind to celebrate or anything because I take nothing for granted in this sport, so my immediate reaction was to point Deontay toward the neutral corner. Even though I thought the fight was over, I wanted to make sure that if it wasn't, we weren't wasting time that we needed, that we'd given Fury extra time. I was pointing Deontay to a neutral corner, and I kept looking back and forth, looking at Deontay, looking at Fury, looking at Deontay, looking at Fury.

Reiss got down on one knee as he counted over Fury's face. At six, Fury rolled over to all fours, and at nine, he was on his feet with 2:11 left in the fight. Reiss pointed to Fury and asked him, "Can you continue? You want to go?" Fury put his arms on Reiss' shoulders. Reiss brushed them away, and following California State Athletic Commission protocol, he pointed to his right and said, "Walk over there, and come back to me." Fury jogged a couple of steps, Reiss wiped off his gloves, and the fight resumed.

Davison: I vividly remember Jack in the locker room [during fighter instructions before the fight] saying, "If you get knocked down, I'll ask you to walk to your left or walk to your right. I'll be checking to make sure that you are OK and that your balance is OK because anybody can just stumble forward." That was what he said, and that's what he did.

Reiss: One of the things I tell these guys in the dressing room before the fight is if you get knocked down -- and I tell everyone the same thing -- and you get up, I am going to ask you, "Are you OK?" I want you to look at me, shake your head up and down, and say yes because then the commission sees his head moving up and down and that he is responding to me. Ninety percent of the guys that get knocked down like that, they get knocked out in the next sequence. So I wanted to make sure people knew I wasn't throwing a lamb to the lions. [Fury] looked great jogging to the side. It was a bonus. I knew for sure he could intelligently defend himself.

Fury: It was like being turned off like a light switch. I didn't feel any pain. There was no feeling. It was just on and off. That was it.

Reiss: When I saw the two punches he got hit with, the right and then the left, I saw that they were thunderous punches, very hard punches, and I said to myself, "Wow, that's a hard knockdown." With my training and my instinct, I realized there wasn't a lot of damage prior to that in the fight. They got hit with a lot of shots, but there were no really hard, devastating knockdowns or head-snapping blows, and I was always taught to count a champion out. Before I waved it off, I wanted to see what I had. I got Wilder to the neutral corner, which he did on his own. I didn't have to do very much. Grabbed the count from the timekeeper. One of the things I noticed is that Fury's right leg was up. To me, that was on his own power, so he wasn't out. I don't know if he was annoyed or taking a rest, but to me if he was unconscious, that leg would have been flopped down. He was holding it up.

Deas: After about the count of five, I remember thinking, how has it not been waved off yet? The guy hasn't moved. Wave it off -- it's over. Then, I think, a split second before it was going to be waved off, he stirs and comes to life. That was like, "Oh, wow, you've got to be kidding me. I cannot believe that he's going to get up."

Fury: I rose from the canvas like a Phoenix from the ashes and got back into it. He hit me with arguably the two best punches he has ever thrown in his career, and it didn't do any good. I just got back up.

Reiss: I didn't think he was out because of his leg, but I expected him to be in bad shape from those punches. I expected his eyes to be closed, but when I got close enough to him, I saw that his eyes were actually open. More importantly than that, as I got down on a knee next to him, he didn't move his head, but his eyes shifted to me. He saw me coming. He looked at me. So I knew he was awake. It makes a big difference. If his eyes were closed, I was waving it off.

Davison: I didn't actually think he was hurt. I just thought he was out. I thought he was out instantly. I thought, "He's out. That's it." And then I actually got into an argument with the commission because I was trying to have a look once he started to get up. Once I started to see Tyson rise, I was trying to assess him. I know Jack Reiss is an experienced referee, but do I need to step in here? I need to assess my fighter. I know that Wilder is a formidable finisher, and the commission started pulling me back. So I got in an argument to say, "Look, I need to have a look at my fighter. Nobody knows him better than me." By this point, by the time I turned back around, Tyson's back on his feet, and Jack Reiss said to him to go to one side, and Tyson just sort of jogged over, and I'm thinking "What the F is going on here?"

Wilder: Honestly, it was a slow count. I think the ref was exaggerating a little bit. Holding eight ... nine. It's seconds. One. Two. Three. It's a second. Not two seconds for each number.

Finkel: Jack is a very good referee, but I felt he made a mistake, not just the count. Fury admitted after he didn't know he got up, didn't know where he was. It was obvious he was concussed, but Jack didn't stop it. And after Fury is up and Jack says do this, do that, 12-14 seconds, for sure. I've never protested, but knowing everything I know, I think he made a misjudgment. But it made the rematch fight bigger.

Reiss: It was the greatest decision I've ever made in boxing. My count was perfect. As I was saying nine, he was rising. And there was no part of his body other than the soles of his feet touching the ground as I was saying nine. He was up. That's it. I've checked it 100 times -- real time with my stopwatch on my phone. It was nine seconds.

Davison: In terms of Wilder's team, I've got a helluva lot of respect for Wilder and his team. I think they're great people, but obviously, what they're arguing over is minimal splits of a second. The actual rule is a 10-second count by the referee's count. It's not a 10-second count. So Tyson doesn't get knocked down as a fighter and starts counting to 10 in his head. He's following the referee's count, and obviously, by the referee's count he's on his feet. Whether it was a split second under, a split second over, we would have had to have respected it if it were the other way around.

Fury: God brought me back and rose me up and let me fight again.

Davison: One thing that Tyson will always, always say is, "You have to nail me to the canvas to beat me." Throughout that training camp, Tyson's best asset is that he was realistic. He'd often say to sparring partners, "Look, if I do get knocked down, I'll wait, get to the eight count, and then I'll stand up. I'll take my time. I'll get back up. But trust me, when I get back up: He'll be in for hell." And he was always very realistic in the fact that that could happen. I'm a firm believer in that by constantly saying that, he subconsciously put into his own head that belief, so that while he's on the ground, it's subconscious for him to say, "Wait till eight. I will be getting up. There's no doubt in my mind that I will get up. If I've got the strength in my body to get up, I'm getting up." And I do believe it was a mix of that and very good conditioning. We trained nonstop for 14 months to get him prepared pretty much every day. And also I do believe that it was an act of God as well.

Reiss: I thought Fury was trying to implore me to not stop this fight, that he was fine when he put his hands on my shoulders. But I didn't want it to appear that he was leaning on me, and that's another reason I made him walk. If, God forbid, I let him go, there's a 6-foot-7, 225-pound tornado about to come bearing down on him. If he gets knocked out or hurt, people will say, "Jack Reiss is an a--hole, Jack Reiss should have stopped the fight, boxing is unsafe." So my job is to convince the doctors and the commission and the crowd that what I am doing is correct, that he is in full control of his body and able to intelligently defend himself.

Deas: Once he got up and Jack started giving him the directions to go left, go right, which we know that's the rule in California -- it's actually a good rule, but it does give you more time to recover. By that point, he was responding. I didn't think he was going to wave the fight off unless Fury stumbled or something like that. At that point, I thought, "OK, we need to go and finish the job."

Fury: Reiss was looking at me like, "Are you OK? Like, you just took massive punches." I said, "Jack, I'm OK." I put both hands on his shoulders to let him know I'm OK. I looked straight in his eyes and said, "I'm OK." Nice and clear so he would let the fight continue. One thing I've always been taught in boxing is if you go down, you have to make sure the referee knows you're OK to continue because at the end of the day, that's the referee's job: to take the safety of both fighters into account.

When the fight resumed, Wilder went into all-out attack mode in an effort to finish Fury, cornering him and landing several heavy shots. But Fury survived and roared back, even stunning Wilder with a right hand. Fury seemed to have cleared the cobwebs from the knockdown, as he was bouncing on his toes and even put his hands behind his back and taunted Wilder with 80 seconds left. As the 10-second warning sounded, Fury was bouncing up and down, and Wilder missed with a big right hand and a left hook at the final bell. They each raised their arms, believing they had won. Fury climbed the ring post, Wilder hugged Deas, and Wilder and Fury eventually had a long embrace before the scores were read.

Davison: I know that Wilder's a formidable finisher, so I'm assessing Tyson and trying to take every little detail in that I can in that last round. I remember a massive left hook landing, and I thought, "Oh, do I need to take action here?"

Deas: Deontay hit him with some shots and backed him up to the ropes and threw an overhand right, and it missed by mere centimeters. It wasn't that Fury dodged it. It was just that Deontay was just a hair -- and I mean a hair -- short on the punch. If it had landed, Fury would have fallen right on his face, and it would have been over.

Fury: The referee was nowhere near stopping the fight. I wasn't hurt. I wasn't hurt at all. Even when he caught me, after he knocked me down, I wasn't shook up. I wasn't even hurt. It was like I was bulletproof. The shots were ricocheting off me.

Davison: I remember shouting out to Tyson and saying, "Grab hold of him. Whatever the ref's doing, it doesn't matter. Do not let him go!"

Deas: Deontay missed the shot, and Fury grabbed him, and when he grabbed him, I thought, "Man, there went our moment. We were on the verge of finishing this thing, but now he's found a way to get through this moment." I was so hopeful. I thought a real significant moment was that moment right there.

Wilder: I didn't know how much time was on the clock. We were just giving them a show. I'm finishing strong, as I was instructed.

Reiss: Any time there's a hard knockdown, where I believe a guy has taken a good shot, when they get up, I change my distance. I stay very close to the action so I can jump in because the percentages are the guy is going to get knocked out. So if you watch it again, you'll see that instead of being 5, 6 feet away, I was right on top of the action.

I wasn't thinking about stopping it. Fury was in full control of his body. He was blocking shots. When a fighter is in trouble, he can do a bunch of things. He can run, hold, take a knee, fight back, bob and weave. The best thing a guy can do for me is run to get the buzz out of his head. If a guy doesn't have his legs, I want him to hold. Tyson moved and held. That told me he was totally conscious of what was going on and trying to survive. Guess what? Twenty or 30 seconds later, Wilder was out of gas from punching him.

Deas: Once Fury did the thing with his hands behind his back, I thought that was completely a mind thing, trying to convince Deontay he was back when I didn't think he was back. I thought we still had a chance for a knockout, but every moment that goes by, Fury is getting a little more clear-headed, in particular when he started firing back. When he's kind of punching between Deontay's punches and somehow is regaining his senses to the point where he's problem-solving, which is the thing you look for with somebody in that situation. I'm thinking I know we got a 10-8 here. I know we got a 10-8 in the ninth. I thought we won the early rounds. I felt really good about it. I thought this was more cementing a victory than salvaging a draw.

Fury: I remember hitting him with some good shots in Round 12. I had him shook up, and that's it. The bell sounded, and I immediately ran around the ring celebrating because me and probably the rest of the world thought I won the fight. I acted like a professional after the fight. It was what it was. Deontay Wilder didn't do anything wrong. He'd done everything he needed to do, and that's it.

Wilder: We were just telling each other "great fight," telling each other we love each other. He was telling me thank you. He was thanking me for the opportunity and different things like that. It was all love.

Davison: That 12th round alone has inspired millions of people across the world in terms of Tyson telling his story [about taking time off to address his mental health] and saying if you get knocked down, you've always got to get back up and keep fighting. It's OK saying that, but it's another thing showing it, and then there's showing it at an elite level, like he did in the 12th round.

Deas: There's no question Tyson Fury is a tremendous fighter and has tremendous resolve and heart to be able to get up from that shot -- not just get up but to be able to get up and somehow work his way back into the round. He's everything we thought that he was. He's a real, real great fighter. That's something we knew anyway, but he showed it. He proved that he's one of the two best heavyweights in the world today. I think you just have to give Fury the credit and say he did something remarkable, and he's a remarkable fighter.

Reiss: Amazing. The only word I can say. Fury truly has an unbelievable heart. He displayed the human spirit that everyone comes to see boxing for -- someone taking a licking and keeps on ticking and refuses to quit. Getting off the mat like that was a really significant moment in boxing history.