ANAHEIM, Calif. -- Cain Velasquez stopped Brock Lesnar late in the first round with a relentless flurry of punches at UFC 121 on Saturday night, claiming Lesnar's UFC heavyweight title.
Velasquez remained unbeaten by outpunching the fearsome Lesnar, the UFC's biggest star and top pay-per-view draw. After a frenetic opening minute featuring huge blows by both fighters, Velasquez kept pursuing the bigger champion and eventually staggered Lesnar across the octagon, with Lesnar stumbling to the canvas several times.
Lesnar (5-2) tried to cover up near the cage, but Velasquez mercilessly rained down blows on Lesnar and eventually broke his guard, forcing referee Herb Dean to stop the fight with 48 seconds left in the round.
While Velasquez (9-0) scarcely made a mistake in the entire fight, Lesnar was left cut and seriously bloodied from Velasquez's punches.
"What can I say? He was better than me tonight," Lesnar said.
Lesnar's third title defense came just four months after his return to the octagon following a yearlong bout with diverticulitis, an intestinal malady that threatened his life and forced him to revamp his training and diet. The former professional wrestler and football player adapted without losing the sheer bulk that makes him the toughest physical matchup in the UFC.
But he had never faced a fighter with the athleticism and well-rounded skills of Velasquez, the former Arizona State wrestler who trains at a famed kickboxing academy in San Jose. Velasquez also drew motivation from the chance to become the first Mexican-American heavyweight champion in a major promotion in either MMA or boxing.
Jake Shields also won a contentious split decision over Martin Kampmann in his UFC debut at Honda ( HMC - news - people ) Center, extending his career winning streak to 15 fights. Matt Hamill beat Tito Ortiz by unanimous decision to keep the former light heavyweight champion winless in the past four years, and Diego Sanchez beat Paulo Thiago by unanimous decision.
The UFC returned to the Los Angeles area for the first time in a year with its most anticipated event of the fall. The main event didn't disappoint - although many fans in the sold-out arena likely didn't expect the result after one round of pyrotechnics in the main event.
The first 30 seconds were nonstop action, with both fighters trading haymakers and kicks. Velasquez eventually pushed Lesnar back against the cage, testing both fighters' strength - and Velasquez held his own despite giving away 2 inches and roughly 30 pounds to Lesnar.
When the punching resumed, Velasquez landed most of the blows. Lesnar stayed in a right-handed stance, but might have had trouble seeing out of his left eye, eventually leading to his stumbles and tumbles against the cage.
Earlier, most fans booed when Shields' hand was raised after a slow, largely uneventful fight with Kampmann. Shields (26-4-1) hasn't lost an MMA fight since December 2004, going through eight promotions since that defeat.
Shields joined the UFC after defending his Strikeforce middleweight championship in April, and UFC president Dana White has touted the San Francisco-based fighter as a likely challenger for Georges St. Pierre, the league's nearly unbeatable welterweight champ.