The Jones-Cormier rivalry has been the greatest in the sport. They are the two best fighters to grace the marquee light-heavyweight class. Their first fight ended in a lopsided decision for Jones, after a prelude to the fight that featured menacing trash talk and a stage-clearing brawl. The stakes were so high Saturday night because both were fighting for more than the belt. They were fighting to determine once and for all whose era this is. The third-round kick ended the debate, coming when Jones seemed to be trailing Cormier in a high-paced, claustrophobic match in which Cormier belted Jones with several punches to the chin, fueling concerns that Jones had ring rust.
“I made it back,” Jones said in a postfight interview conducted on his knees in the fighting cage. “It’s never over. As long as you never quit, it’s never over. I’m back here.”
Jones set aside the animosity both had shown before the fight to offer good words for Cormier, whom he called his biggest motivator. (In addition to the belt, Jones will receive a yet-to-be determined cut from the pay-per-view revenue and a $50,000 bonus.)
“He has been a model champion, a model husband, a model father, teammate, leader, and I aspire to be more like that man,” Jones said right after the fight. “Unfortunately, we’re opponents, but outside of that, he is a true champion for the rest of his life.”
The question now is what comes next.
Jones has wiped out the division once before, and it has yet to properly replenish. The best fight probably would be a rematch against Alexander Gustafsson, the Swedish fighter who was his toughest opponent.
But Saturday night, to raucous applause, Jones called out Brock Lesnar, the 40-year-old, semiretired former U.F.C. heavyweight champion and occasional professional wrestler. It would be a megafight that could slip into the mainstream, as well as a dubious one, akin to the coming boxing match between Floyd Mayweather Jr. and McGregor. In all likelihood, it would be an easy paycheck for Jones.
Cormier’s future, however, is murky but probably bleak.
“This is my story,” Cormier told me in June. “He gets to play a part.”
In Jones’s absence, Cormier achieved his dream of becoming champion. But it felt hollow. He had turned professional eight years ago after a celebrated 20-year career in international wrestling yet could not realize his lifelong dream of being the best in the world as long as Jones was inactive. He believed a lifetime of combat, pain and heartbreak would culminate in a victory over his rival.
But true greatness, like Jones’s, is unyielding.
“I don’t know, man,” Cormier, weeping and still dazed from the knockout, said in the cage. “I guess if he wins both fights, there is no rivalry.”
It was devastating. Cormier will almost surely never fight Jones again. Now 38, he will probably retire a onetime U.F.C. champion, a future Hall of Famer, one of the best fighters to ever walk into a cage. But he’ll never be the best.
If his purpose for fighting was truly to be the best ever, then his story will end with him falling just short. It’s a testament to the two-time Olympic wrestler’s ability and his ambition that this feels something like a disappointment.
The question that Cormier, his moment past, must now answer is why he fights.
“A fighter in his heart” is how Cormier’s coach, Javier Mendez, described him. “He is a fighter, was a fighter, will die a fighter.”
It’ll be fascinating to see how Mendez’s words manifest. Cormier has competed in combat sports for all but 10 years of his life. He began his mixed martial arts career as a heavyweight; the reason he faced Jones at all is that he vowed never to fight his close friend and training partner, Cain Velasquez. Velasquez is fighting for the U.F.C. heavyweight title in October, and his presence would ostensibly block Cormier’s extending his career there.
“We all have our day, right?” Cormier said to me before the fight. “You don’t leave as the man most times.”
After years in poverty, Cormier is a millionaire and has a lucrative second career in place as a studio analyst. Saturday night’s events have shown him to be a bit character in a greater fighter’s tale. Cormier never needs to fight again; if he does, it will be because he has to. In the end, the story Cormier has told himself will be just that — a story.
An earlier version of this article incorrectly stated the age of Jon Jones when he defeated Maurício Rua. Jones was 23, not 24.