Kamaru Usman pushed Jorge Masvidal up against the cage at UFC 251. He struck Masvidal with his shoulder, stomped Masvidal's feet and dug in with hard punches to the body.

With an opponent coming in on a week's notice, Usman's strategy was clear: grind and wear Masvidal out. And it worked completely.

Usman defeated Masvidal via unanimous decision (50-45, 50-45, 49-46) in the main event of UFC 251 on Sunday morning in Abu Dhabi, United Arab Emirates. With the win, Usman retained his UFC welterweight title.

Usman vs. Masvidal came together only in the past eight days. Usman's scheduled opponent, Gilbert Burns, tested positive for the coronavirus on July 3, just hours before the UFC charter was set to leave Las Vegas for Abu Dhabi. Over the Fourth of July holiday weekend, the UFC was able to come to terms with Masvidal -- who balked at the promotion's initial offer for the fight six weeks ago -- to fight for the 170-pound title as a late replacement.

"'[Masvidal] is the biggest, baddest dude out there right now," Usman told UFC play-by-play announcer Jon Anik after the fight. "I had to switch gears and prepare for him on a week's notice. ... I had to make a mental shift. I trained for Gilbert. I had a completely different game plan."

The addition of Masvidal, one of the UFC's biggest stars, actually made the fight more highly anticipated. Masvidal and Usman had been feuding since a verbal altercation on Super Bowl radio row back in February.

After Sunday's meeting, the two men showed each other respect. Masvidal told Usman as the two embraced that they would "run it back."

UFC president Dana White later said in his post-fight news conference that Burns would be next for Usman.

"I think that Gilbert Burns and Kamaru Usman is going to be a really, really good fight," White said.

The bout took place at the recently constructed Flash Forum on Yas Island, which the UFC has branded "Fight Island" for this monthlong stretch of events. The facility is inside of a "safe zone" amid the coronavirus pandemic, where only those who have been tested multiple times for COVID-19 are allowed. Those people include members of the UFC traveling party -- fighters, corner people, staff, etc. -- and local workers.

Coming in, Usman was tied with Israel Adesanya for sixth on ESPN's top pound-for-pound MMA fighter list. Masvidal is No. 2 at welterweight, just below Usman.

Usman's 12 straight wins ties lightweight champion Khabib Nurmagomedov for the longest active winning streak in the UFC. That figure also ties Georges St-Pierre for the longest winning streak in UFC welterweight history.

Masvidal started out hot in the first round, pushing the pace and landing hard kicks to Usman's legs and body. Masvidal landed some hard right hands, too, though Usman was never in danger.

It was pretty clear Masvidal was attempting to finish things early since he was coming in on short notice without full preparation. Usman was able to weather that early storm and grind Masvidal's offense to a halt beginning in the second round, which led to plenty of Usman pushing Masvidal up against the cage and taking him down. Masvidal had two cuts open up in the second due to incidental clashes of heads.

"It played out the way I thought it might. I thought if Jorge didn't catch him with something, that's the way the fight would go," White said. "[Masvidal's] takedown defense was unbelievable. He would get taken down and get back up against Usman, which is tough to do. He did it for five rounds and did what he could do. Usman is a beast, man."

Whenever Masvidal was able to get separation, he remained dangerous, even into the closing seconds of the fifth and final round. Masvidal closed the fight by throwing a flying knee and hard kicks. None landed with any significance and Usman held on for the comprehensive victory.

"I'm just at a level better," Usman said. "I have more tools in the toolbox. And when I need to pull them out, I can pull them out and use them."

Usman (17-1) has never lost in the UFC. The Nigerian-born Florida resident has not lost since his second pro bout, in 2013. Usman, 33, was coming off a fifth-round TKO over Colby Covington at UFC 245 in December, the latest UFC title-fight finish ever. This was Usman's second title defense.

Masvidal (35-14) stopped Darren Till, Ben Askren and Nate Diaz within an eight-month span last year, making him one of the hottest fighters on the UFC roster. The 5-second KO of Askren was the quickest in UFC history. Masvidal, a 35-year-old Miami native, had 48 career fights coming in, which was the second-highest total ever for a fighter competing in his or her first UFC title bout.