Leon Edwards’ last-minute, out-of-nowhere head-kick KO of Kamaru Usman in a fight he was about to lose is the stuff that happens once every two or three decades. Rarely in professional sports does an athlete or a team turn a certain loss into an emphatic win the way Edwards did Saturday at Vivint Arena in the main event of UFC 278 in Salt Lake City, Utah.

After a strong first round that he clearly won, Edwards struggled most of the rest of the way. Usman, who entered the fight with 15 consecutive wins in the UFC, was a minute away from tying Anderson Silva’s promotional record of 16 wins in a row. It’s arguably the greatest record in the sport.

At the end of the fourth round, Edwards’ corner was irate at what seemed to be an acceptances of his fate.

“Come on, man! What’s f***ing wrong with you?!” one of the coaches shouted. At that stage, UFC broadcaster Din Thomas said Edwards appeared broken.

But for most of the fifth round, the harsh comments didn’t work because nothing changed. As the clock inched toward one minute, Edwards showed no urgency. UFC broadcaster Daniel Cormier suggested Edwards was content to run out the clock and make it the five full rounds to get a moral victory.

In a blink, it changed and Edwards changed the course of MMA history.

He threw a jab, which wasn’t a particularly fearsome or hard shot. But a lot of fighters throw that jab to try to blind an opponent before following with a right hand they hope does damage.

That’s what Edwards’ jab seemed designed to do, and boy, did it ever lead to some damage.

Usman leaned to his right, which turned out to be a monumental mistake. Because even before Edwards’ jab landed, he was throwing the kick. Usman leaned into the exact spot where the kick was coming.

It landed on the jaw and Usman was down and out in an instant.

Over was his championship reign, his perch atop the pound-for-pound list and his chance to tie Silva’s consecutive wins record, which now looks ever harder to approach, let alone surpass.

Edwards became the first Jamaican-born UFC champion with the wildest finish of a UFC title fight ever.

There are few plays in sports that match it. In a 1978 NFL game, the New York Giants had the ball with 31 seconds and a 17-12 lead over the Philadelphia Eagles. Kneel-downs weren’t allowed at that time, but the Eagles had no timeouts remaining. All Giants quarterback Joe Pisarcik had to do was make certain he made a clean hand-off to Larry Csonka. His attempt to hand off to Csonka was bad, and the ball was free. Eagles defensive back Herman Edwards scooped it up and took it in for unlikeliest win in NFL history.

But that was a meaningless late-season game between two bad teams.

Edwards scored his dramatic victory over one of the greatest UFC fighters of all time as the clock was running out and his dreams of hoisting the belt were about to be snuffed.

“I was listening to the commentary and [broadcasters Joe] Rogan and [Jon] Anik and DC [Daniel Cormier] were dead on with everything that they were saying on what Edwards needed to do and what he should be doing,” UFC president Dana White said. “As soon as they were saying it, Edwards lands the head kick.

“You think of everything that was on the line for Usman tonight — and Usman fought with absolute and total confidence all night — and he fought the perfect fight. … He couldn’t have fought a more perfect fight until the last minute.”

Edwards fought a perfect first round. He became the first man to take Usman down in Usman’s UFC career in the first, and it was significant because he wound up getting Usman’s back.

For a brief time, it appeared he might choke Usman out in the first, but the champion remained calm and worked his way out of it. Still, Edwards clearly won the first.

And then Usman turned into Usman again. He mixed aggressive forward pressure with punches, elbows and takedowns and was beating Edwards in every aspect of the game over Rounds 2, 3 and 4 and in the first four minutes of the fifth.

But the rounds are five minutes long, not four, and Edwards still had time. He took nearly all of it, but he got it done in a resounding manner.

When the kick landed, Edwards knew he’d won it. He instantly raised his arms skyward and began celebrating even before referee Herb Dean could officially call it off.

The suddenness of the ending in a championship moment was sort of like Bill Mazeroski’s bottom-of-the-ninth home run for the Pittsburgh Pirates in Game 7 of the 1960 World Series to defeat the New York Yankees.

Even that wasn’t the same, though, because Mazeroski was the lead-off hitter in the bottom of the ninth and the game was tied 9-9 when he came to the plate.

Villanova’s Kris Jenkins hit a three-pointer from the top of the key in 2016 as the buzzer sounded to defeat North Carolina and win the NCAA men’s basketball championship for the Wildcats. But if he’d missed, the game would have gone to overtime. Similarly, in 1983, Lorenzo Charles’ dunk with one second left led North Carolina State to the national championship victory over Houston, but if he didn’t put it in, the game was going to overtime.

Edwards’ win will go down not just as the most dramatic in UFC history but in all of sports history considering the stakes and the circumstances.

“All the doubters said I couldn’t do it,” a jubilant Edwards said. “You all said I couldn’t do it. Well, look at me now. Look at me now!”

He’s on top of the world, a remarkable story of a kid who seemed destined either to die early or spend much of his life in jail given the circumstances of his birth and early life. But he found MMA and, well, both he and MMA are all the better for it.

At the post-fight news conference, his voice was scratchy, and he apologized because he’d been crying.

There aren’t many better rags-to-riches stories than this guy.

“Everyone knows my past but I’ve said all week that’s the way it was meant to go to build me into the man I am today,” he said.

The man he is today is the UFC welterweight champion of the world.