LAS VEGAS-An interim heavyweight champion was crowned and a mixed martial arts star proved that size and athleticism alone cannot win a match at UFC 81 on Saturday.

With the several of his professional wrestling cohorts watching, former WWE star Brock Lesnar was forced to tap out by a bloodied Frank Mir in the first round at the Mandalay Bay Resort and Casino.

But the big man had his moments.

Lesnar leaped to attack with the speed and fury he was known for as a pro wrestler and amateur wrestler. The audience of more than 10,000 seemed to feel the former UFC heavyweight champion Mir had bitten off more than he could withstand.

Then it happened.

After sustaining several blows and bludgeoned to the ground by the powerful Lesnar, the referee stopped the fight and for a second it looked like the fight was over. But instead, it was referee Steve Mazzagatti penalizing Lesnar for illegally pounding Mir behind the head. The fighters were separated and back they collided again.

“I had Brock Lesnar dropping elbows on my head,” said Mir (11-3), who had visible bleeding around his eyes and forehead.

Lesnar attacked Mir in the same fashion he attacked the little-known Korean fighter he faced in his first MMA foray last June, but this time he was facing a former champion and suffered the consequences for his over confidence. Suddenly, with the Undertaker, Stone Cold Austin and Kurt Angle watching with eyes glued to the Octagon, within seconds Mir had changed his plan of attack and suddenly was attempting an arm bar and a leg bar. The leg bar stuck.

At 1:30 of the first round Lesnar was stretched out and tapping out to the amazement of many in the crowd.

“He got me tonight,” said Lesnar (1-1) graciously. “He’s a better fighter.”

Mir had planned to attack Lesnar from a standing position but quickly learned he was overpowered and stepped into plan B which saw him take the fight to the ground for jujitsu 101. It worked.

“When he pulled out of an arm bar I switched to grabbing a leg,” said Mir.

The quick reversal of fortune from victim to victor had the crowd in a frenzy as Mir jumped to his feet with his hands spread out as if to say “I told you so.”

Even Lesnar was impressed.

“I came out fast to pressure him,” said Lesnar. “I heard in the past there was a question of his heart.”

Though the former pro wrestling star lost, his quickness and power definitely left a signal to other heavyweights that a reckoning is coming and his name is Lesnar.

“You win some and you lose some,” said Lesnar after the fight. “I’d like to win them all, but you can’t.”

Nogueira wins

Brazil’s Antonio Nogueira withstood two rounds of pounding from former heavyweight champion Tim Sylvia (26-4) but once he took the fight to the ground it was over.

Despite two knockdowns from big right hands by Sylvia that opened a nasty cut over Nogueira’s left eye, the Brazilian kept waiting for his moment to take down the much taller Sylvia. In the third round he grabbed a leg while both were on the ground then switched to a guillotine choke that had Sylvia immediately tap the ground for the referee to stop the fight.

Nogueira is the interim UFC heavyweight champion. Randy Couture holds the actual championship but is mired in the court battle with UFC.

“He’s a giant. I got caught with many punches by him,” said Nogueira (31-4-1) who formerly held the Pride FC heavyweight championship. “I tried to get an ankle lock then I got his neck and it was in very tight.”

Referee Herb Dean stopped the fight at 1:28 of the third round.

Other bouts

Nate Marquardt (29-7-1) struggled in the first round against the very experienced Jeremy Horn (88-17-5), but discovered an opening in the second round for a guillotine choke and forced the Utah fighter with more than 100 fights to submit. The referee stopped the fight at 1:37 of the second round.

“Jeremy Horn’s a stud,” said Marquardt who took down Horn twice in the first round and was unable to take advantage because of Horn’s Gumby-like flexibility. “He was shooting with his head down and I realized it in the second round.”

Brazil’s Ricardo Almeida (9-2) had been out of action for nearly four years but returned to the Octagon and needed only 1:08 to prove his skill was intact against Alaska’s Rob Yundt (7-1). A guillotine choke with the arm inside forced Yundt to submit in the first round of a middleweight bout.

“I’m one of the few guys who know how to do that,” said Almeida of his choke over Yundt. “I knew he was going to drop to his knee.”

Sacramento’s Tyson Griffin (11-1) won an unpopular unanimous decision over Brazil’s Gleison Tibau (27-4) after three rounds. Despite six takedowns by Tibau, it was Griffin’s punches and ability to escape the takedowns that won over the judges 30-27 in a lightweight battle.

“I wasn’t happy with the outcome,” said Griffin. “I was looking for that impressive finish. I think that’s why I was so patient.”

Chris Lytle (35-15-4) jumped on Oklahoma’s Kyle Bradley (13-5-1) with several hard right hands and pounded him out in 33 seconds of the first round. Bradley, semi-unconscious, was still fighting with the referee long after the welterweight fight was ended.

“I hit him early with my right hand” said Lytle. “I tried to get on him early anyway I could.”

Las Vegas fighter Marvin Eastman (15-7-1) dropped down in weight to fight Terry Martin (18-4) and found success in a middleweight contest. The last round proved to be the best for Eastman who used kicks and elbows effectively. The judges scored it 29-28, 30-27 twice for Eastman.

Pennsylvania’s Tim Boetsch (7-1) out-slugged Oklahoma’s David Heath (9-3) and drove him to the floor with a knee followed by a ground and pound attack. The fight was stopped at 4:52 of the first round for a technical knockout in a light heavyweight fight.

In a strange decision, the judges scored a unanimous decision win for Robert Emerson (9-6-1) over Japan’s Keita Nakamura (14-3-2) in a lightweight contest. Though it looked like the Japanese fighter won two rounds, the judges scored it 30-27 twice and 29-28 for Emerson. The crowd disapproved.