SEVEN MINUTES INTO Wednesday's Game 3, it seemed the Boston Celtics were in danger of loosening their grip on the NBA Finals.

The Dallas Mavericks had leapt out to a 25-12 lead, a run punctuated by a pull-up 3-pointer from former Celtic Kyrie Irving, and the partisan home crowd inside American Airlines Center was in a frenzy. Boston, already without Kristaps Porzingis after the center suffered a rare tendon injury in his left leg in Game 2, suddenly had the look of a team on the defensive, rather than one holding a 2-0 series lead.

But when it looked like things were about to go haywire for the Celtics, Jayson Tatum ensured they didn't. His eight points during an 18-6 run to close the first quarter got Boston within one point. Tatum ended the first half with 20, surpassing his point totals in both Games 1 and 2, to keep the Celtics close with Dallas on a night when it looked like the Mavericks could run away with Game 3 and shift the series.

Instead, Boston propelled itself into the lead and claimed a 106-99 victory to move within one win of an NBA-record 18th championship.

It was just the latest example of the 26-year-old Tatum -- Boston's ever-present, ever-dependable, ever-versatile forward -- finding the right way to help his team to a crucial victory.

"I think from our experiences over the past couple of years, the thing that we've really gotten a lot better at is not relaxing, not being complacent," Tatum said Thursday ahead of Boston's closeout opportunity in Dallas (Friday, 8:30 p.m. ET, ABC).

"From game to game or series to series, we always want more."

The same could be said for critics who pick at Tatum's star-studded résumé for not also including a ring. But Tatum's rare combination of versatility and durability -- both to withstand years of heavy minutes in deep playoff runs and the criticism that comes with being the face of the NBA's winningest franchise -- is at the core of everything this Celtics group has accomplished.

"If you listen to the narrative, you would think I was, like, 32," Tatum told ESPN earlier during the Finals. "No, I'm 26 years old. We've just been knocking on the door for a long time.

"And I get it. I want to win more than anybody can imagine."

AS THE CELTICS have progressed through the 2024 NBA playoffs, star availability has been an ever-present topic.

Boston's opponents in the Eastern Conference playoffs -- the Miami Heat, Cleveland Cavaliers and Indiana Pacers -- were missing All-Stars in Jimmy Butler, Jarrett Allen, Donovan Mitchell and Tyrese Haliburton for part, or all, of each series.

Milwaukee Bucks two-time MVP Giannis Antetokounmpo didn't play at all in these playoffs. Neither did New York Knicks star forward Julius Randle. Last season's MVP, Joel Embiid, was hobbled during the Philadelphia 76ers' entire first-round defeat.

The Celtics themselves have been without Porzingis for the majority of their games in these playoffs. Luka Doncic, Tatum's counterpart as the face of the Mavericks, is dealing with a litany of injuries.

And then there's Tatum, who has never missed a playoff game in his career, continually playing heavy minutes for his team.

"He never wants to sit out," Celtics guard Jrue Holiday said. "I've played with a lot of players. When you have your best player who wants to play every single game, takes the game that seriously, even if they're banged up with an ankle, knee, whatever it is, still goes out there and plays, I think it shows a lot."

Tatum credits his durability to his close relationship with Celtics trainer Nick Sang. But as a rookie, Tatum didn't immediately appreciate the long-term benefits to what Sang was asking him to do.

"We had a rough start," Tatum said with a smile.

"I was a kid, so I could come in and just tie my shoes up and go practice and play," he said. "I always loved to workout and shoot, but, like, my first year I never went to lift or get treatment or recover.

"I was 19 and, you know, I could just wake up and go play, feel fine."

That mindset shifted in spring 2019, when the Celtics faced the Pacers in the first round of the playoffs during Tatum's second season. At that point, Tatum said, he was dealing with shin splints, and it was the first time he needed regular work on his body to get himself ready to play. Sang's messages preaching recovery and injury prevention began to register.

"He was telling me how things in the weight room can prevent certain injuries," Tatum said. "And that summer, and that next season was really when I started to really notice and take ownership in all the other stuff."

Over time, that has led to a reevaluation of Tatum's daily life, from tweaking his workout regimen to hiring a personal chef to transform his diet.

"He's been gifted with this emotional stability and this mental toughness from whenever I first met him," Celtics' head coach Joe Mazzulla said. "All he has ever wanted to do is get better, whether that was figuring out how to be better for his teammates or figure out how to be better for his coaches. ...

"So he does it in every area, not just like basketball. Like he does it as a parent. He does it in the strength and conditioning room. Like the relationship he has with Nick. He's just seen how everything impacts his career, and he takes full advantage of that."

But Tatum's steady presence on the court, alongside Boston's repeated trips to the latter rounds of the playoffs, has at times been both a blessing and a curse.

FRIDAY'S GAME 4 will be Tatum's 112th career postseason game, the third most in NBA history by a player age 26 or younger, behind Hall of Famers Tony Parker (122) and Kobe Bryant (119). Tatum's 67 postseason victories before turning 27 are fourth all time, behind Bryant (76), Parker (75) and Magic Johnson (70).

Since being drafted in 2017, Tatum leads the league in playoff games, minutes, points and free throws made, and is in the top five in rebounds, assists, steals, blocks and 3-pointers made.

Last month, Tatum earned his third straight All-NBA first-team selection, a feat only four other players have accomplished over the past decade: Tatum's adversary in these Finals, Luka Doncic, plus James Harden, Giannis Antetokounmpo and LeBron James. Expand the range to 25 years and the list includes Tim Duncan, Shaquille O'Neal, Jason Kidd, Kobe Bryant, Dirk Nowitzki, Steve Nash, Dwight Howard, Kevin Durant and Chris Paul.

"He is our most important player," Celtics center Al Horford told ESPN, when asked about the importance of Tatum's availability on a nightly basis. "And when you know that you have your best player available all the time, No. 1, I feel like it raises the level for all of us to be like, 'Oh, we better make sure that we're available, and that we're good to go.'"

Tatum's success has allowed him to become one of the league's biggest and most marketable stars. He has made five All-Star teams, won an Olympic gold medal in Tokyo and could win a second in Paris later this summer.

Boston has played 129 playoff games since the start of 2016-17 -- the most without a title over an eight-season span in NBA history. Much of that criticism has fallen on Tatum, who over time has learned to embrace the scrutiny.

"It actually helps me," Tatum said. "I understand I play for the Celtics, and they want us to win every year, and we have been close. And a lot of times, you hear the noise around you about, 'He hasn't gotten it done. He can't do it. He can't be the best player.' ... Yeah, I haven't won yet and I'm still only 26, but I've done a lot of special things.

"And we're all human, right? Sometimes you just need to be reminded like, 'I can do it. It's just a matter of time.' I'm definitely trending that way [toward] all the guys I looked up to."

In these playoffs, he has played a large part in getting both himself, and the Celtics, on the verge of accomplishing what they've been waiting years to do. Tatum is a league-best plus-162 in this year's postseason and leads Boston in points (25.2), rebounds (10.1) and assists (6.2).

In 2022, Tatum and the Celtics had their chances -- including holding a 2-1 Finals lead over the Golden State Warriors before dropping the final three games of that series. Now, after two years filled with more playoff heartbreak and narratives around his legacy, Tatum is hoping to use that experience to lift himself, and this year's Celtics, into the TD Garden rafters.

"Everybody knows we only hang up championship banners, and it's been a while since we've won one," Tatum said Thursday. "Ever since '08, the goal is to win another one every single year. Gotten close plenty of times.

"It's just an honor. It's an honor to wear this jersey. It's an honor to follow in the footsteps of some of the best players ever. Being a part of Celtics history entails that you've got to win a championship.

"Every kid growing up playing basketball dreams about being in the Finals, dreams about winning a championship. I'm no different than anybody else."