On a night when he stood alone atop the UFC heavyweight division, Brock Lesnar’s behavior -- not his destructive, one-sided victory against Frank Mir -- was the subject of post-fight discussion on Saturday at the Mandalay Bay Events Center in Las Vegas.

Lesnar unified the heavyweight championship in only his fifth professional appearance, as he bullied his way to a technical knockout against Mir -- the only man to defeat him -- in the UFC 100 main event. His tirade afterward -- which included a low blow to the UFC’s primary sponsor, Bud Light, waving his middle fingers at the audience, taunting Mir and exposing plans for a post-fight sex romp with his wife -- drew the ire of UFC President Dana White.

The 32-year-old Lesnar claimed he was headed out to drink a Coors Light because Bud Light would not pay him any money. One of the UFC’s highest-paid fighters, he made $450,000 in disclosed pay for his TKO victory against hall of famer Randy Couture at UFC 91 in November.

“I was blown away,” White said. “I don’t think in the history of the UFC we’ve had anybody do that. It’s not who we are, and, to be honest, it’s not who he is. You hang with these guys personally, and you get to know them. If he was a dick, I’d tell you right now this guy is a psycho and I don’t know what I’m going to do with him. He’s not. He’s a smart guy. The sponsorship thing was the craziest thing I’ve ever heard in my life.”

Lesnar’s antics drudged up memories of his days as a World Wrestling Entertainment superstar, when showboating and pushing the envelope of taste were encouraged and profitable. White claimed he confronted the apologetic champion in his dressing room after he left the Octagon.

“Brock went so far over the top, I can’t even put it into words,” White said. “WWE -- that’s what it is. We had a talk. We talked like men, and he said he was sorry. He said, ‘I’m embarrassed by what I said.’ I take his word for it this time.”

Lesnar issued an apology at a post-fight press conference.

“I acted very unprofessionally after the fight, and I’ll leave it at that,” he said. “You guys ask me all the time if there’s anything I can drag over from WWE, and I guess you’ve seen a little bit of that tonight. I’m used to selling pay-per-view tickets. Dana came back, and we had our whip-the-dog session. I screwed up, and I apologize.”

Lesnar expressed specific remorse to Bud Light.

“I’m not biased,” he said. “I drink any beer.”

This story was updated at 4:35 p.m. ET on July 12.