LAS VEGAS — 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.
In the co-main event, Diaz (15-7) backed up his tough talk and rude behavior in a fight that had the sellout crowd on its feet as he battered Cerrone, nearly a 3-to-1 favorite in the MGM Grand sportsbook for most of the three-round standup fight.
Diaz, the brother of bad-boy welterweight Nick Diaz, picked apart Cerrone's defense for most of the fight, leaving Cerrone bloody after his first loss in seven fights since September 2010.
Cerrone (17-4) knocked down Diaz at least a half-dozen times with kicks and leg-whips, but Cerrone refused to fight Diaz on the ground, repeatedly allowing Diaz to get up.
The unusual strategy showed respect for Diaz's ground skills, but also minimized the importance of those knockdown shots in the eyes of the judges, who scored the bout 30-27 twice and 29-28 once, all for Diaz.
Hendricks (12-1) ascended to elite status with one sneaky left hook that caught Fitch (27-4-1) right on the button, flattening the favored San Jose fighter, whose return from a 10-month absence was stunningly brief. Hendricks, a two-time NCAA champion wrestler at Oklahoma State, completely stunned Fitch, who had lost just one fight since December 2002.
Early in the pay-per-view portion of the card, Swedish light heavyweight Alexander Gustafsson (13-1) stopped veteran Vladimir Matyushenko with a perfect left hand midway through the first round.
Unbeaten featherweight Jim Hettes got new fans' attention with a comprehensive thrashing of veteran Nam Phan, repeatedly threatening to finish the fight with strikes and ground work.