(AP)Brock Lesnar retired from mixed martial arts after Alistair Overeem stopped him with one vicious kick to the body at 2:26 of the first round in their heavyweight bout at UFC 141 on Friday night.
Lesnar is the UFC's biggest pay-per-view star and the former heavyweight champion, but his return from a 14-month injury absence ended with Lesnar staggering and crumpling against the cage. He couldn't recover from a kick from Overeem (36-11), the 6-foot-5 Dutch kickboxing star making his UFC debut.
Lesnar (5-3) is a former NCAA champion wrestler and pro-wrestling star who rose swiftly to the top of MMA. But he has fought just three times in the past 2½ years while dealing with bouts of diverticulitis, a lower-intestinal ailment that nearly killed him.
"I've had a really difficult couple of years with my disease, and I'm going to officially say tonight is the last time," Lesnar said. "This is the last time you'll see me in the octagon."
The 34-year-old Lesnar's announcement stunned fans who realized he faced a difficult matchup in the UFC's traditional end-of-the-year event in its hometown. The matchup was a classic MMA clash of styles, with Lesnar's brutal wrestling contrasting sharply with Overeem's vicious striking.
Overeem is three years younger but much more experienced than Lesnar, hurting the former champion at least twice earlier in the round with knees to the stomach while Lesnar failed in his attempts at takedowns.
"I promised my wife and my kids if I won this fight, I would get a title shot, and that would be my last fight," Lesnar said. "But if I lost tonight ... you've been great."
Overeem will get the next shot at UFC heavyweight champion Junior Dos Santos, who watched from a seat near the octagon.
Overeem is a champion kick boxer who has fought in multiple promotions over the past decade, winning titles in Dream and Strikeforce with nearly unbeatable striking and size. He joined the UFC in September, finally presenting his formidable skills and intimidating physique to the sport's largest audience.
UFC President Dana White might have given an immediate title shot to Overeem if the timing had been better, but Dos Santos only claimed Velasquez's belt in early November. Overeem welcomed a debut against Lesnar, even guaranteeing a knockout in the first two rounds.
"Today was all about bad intentions," Overeem said. "First or second round, I promised. ... I worked on my takedown defense a lot. Brock is an excellent wrestler, so I had to step up my game."
The undercard at the MGM Grand Garden featured two upsets: Lightweight Nate Diaz won a bloody unanimous decision over Donald "Cowboy" Cerrone with superior boxing, and Johny Hendricks stopped welterweight star Jon Fitch with one punch just 12 seconds into their bout.
Lesnar hadn't fought since losing his heavyweight belt to Cain Velasquez in October 2010, cancelling a bout against Junior Dos Santos last June in Vancouver after another bout of diverticulitis, the lower intestinal ailment that nearly killed him a year earlier.
Lesnar became the UFC's biggest pay-per-view star in remarkably short order after taking up MMA, and the hulking former NCAA wrestling champion and fake pro wrestler kept his unparalleled popularity during his absence. Lesnar used the time off to modify both his diet and his standup game, attempting to improve his biggest weakness.
As it turned out, Lesnar couldn't improve enough to contend with the supremely skilled Overeem, who embraced Lesnar afterward.