Down the red carpet came the impersonator with the sewn-in hairline, the magician with the elevator shoes, the comic with the face so sutured it could be an artist's rendering -- even a man in a lime-green zoot suit carrying a faux-silver chalice made of rhinestones.

All of them were there to see a Las Vegas act try something unheard of -- the truth.

This was opening night for "Mike Tyson: Undisputed Truth -- Live on Stage," his six-night, one-man, is-he-really-going-to-do-this? show at the MGM Grand.

The mind reeled. Would the crowd be issued ear muffs? Would he release his pigeons? Would he eat your children?

"I don't think so," guessed comedian George Lopez. "He's a vegan now."

Instead, Tyson surprised them with medical-grade honesty. For two hours, it poured out of him like lava, raw and awful and sweet and funny and disgusting. He mangled words and got hopelessly lost and then found paths you'd hope he wouldn't. And yet, if you liked comic tragedy, he had you at, "I'm Mike Tyson. I used to knock [expletives] OUT."

Performing in The Hollywood Theater, the usual home of David Copperfield, Tyson magically turned the 740-seat venue into the world's largest confessional booth. Tales of psyche wards, hookers, robberies, beatings, pits of loneliness and zeniths of championships. He forgave on one hand and accused -- "Robin Givens used me" ... "I had no idea I was going to meet the devil (Don King)" -- with the other. He would celebrate his three years of sobriety one minute and then shout out to "my old cocaine buddies in the crowd" the next.

You should've heard what he left out.

"I didn't talk about getting a prison official pregnant," he told me for a "SportsCenter" interview after the Saturday show.

Excuse me? You got a prison official pregnant, while you were IN prison?

"Oh, yeah. In prison, stuff happens. But she had no baby."

He left out how he came to have a tattoo on his face, or how he rode $300 million straight into bankruptcy, or all the time he spent on a morphine drip, for the pleasure of it.

"I just liked morphine," he told me, "but I had to take a lot of it because it didn't stay in your system for a long time. ... And I'd have my cocaine, and I had my marijuana, and I had my Cialis and Viagra and my little friends all sitting there. That's just how I lived my life."

Ohh-kay, maybe he'll save those for the sequel. The original alone was enough to singe eyebrows.

Working from a script mostly written by his wife, Kiki, based on years of his storytelling, standing on a spare stage with only a band, Iron Mike Tyson tried to explain what it was like to be lionized for his violence inside the ring and vilified for it outside.

Remember when Tyson was on the cusp of being world champion under his Catskills mentor Cus D'Amato? Turns out he would return to his hometown of Brooklyn to rob people with his gang-banger friends. "We were about to do this guy," he recalls, "but my friend, he had a .38 [revolver] in his belt, and he says to me, "Get the f--- outta here. Go back to them white people. Them white people love you. I wish I had some white people to love me.' That guy was dead a week later. I wouldn't be standing here if it weren't for him."

Remember in 1997, when Tyson bit both of Evander Holyfield's ears, the beginning of the end? "They sent me to the Mayo psych clinic," he told the crowd. "A nuthouse. And there was this little white lady in there, looking at me. She looked like Thelma from Scooby Doo. She asked me why I was in and I said, 'Aw, these people think I'm crazy 'cause I bit a guy in a fight. But he wouldn't stop head-butting me!' She said, 'Oh, you was in a fight!' I was so grateful she said that. She made me feel like a human being again."

Remember when Tyson was arrested for cocaine possession after nearly ramming a parked sheriff's car in Scottsdale in 2006? He wasn't supposed to be. "The cops told me, 'Mike, we were gonna let you go, but you just came right at us!' I was driving right at them. They were going to shoot me! If I hadn't gone to rehab right then, I'd have been a dead (expletive)."

It wasn't exactly Sinatra at the Sands. There were too many times you couldn't understand him, or he'd KO the language ("I had my mother's coffin resumed"), or he'd murder songs, turning the night into a kind of a Cirque du Sore Ears. But if you could abide all that, you were rewarded with gold nuggets.

Did you know that as a boy, he saw his mother, Lorna, throw boiling water, cups of lye and hot coffee in the face of her boyfriend, and yet would see her get back with him the very next week?

Did you know he was close friends with John F. Kennedy Jr., and that he warned him not to take the light-aircraft flight that killed him in 1999?

Did you know that before his infamous 1990 loss to 42-to-1 underdog Buster Douglas in Tokyo, he "smoked pot," "didn't take training too seriously" and went through "too many of them Japanese prostitutes"?

"I shoulda won that fight," Tyson added. "That ref [Octavio Meyran] hated my guts. I knocked [Douglas] down in the eighth but that a--hole gave him 13 seconds to get up!" (Actually, Douglas was staring at the ref the whole time. OK, so not all the truths were undisputed.)

It was a schizophrenic two shows I saw. He'd talk of moving on and then insist that 1992 rape victim Desiree Washington made it all up. He'd talk endlessly about his "mad-dog" hunger for boxing glory and yet he hardly spent two minutes on all of his fights, combined. At one point, he confessed that he was terrified of failing and comedienne Rosie O'Donnell hollered out, "You're doing great, Mike!"

If not great, then bravely.

Broke boxers have forever been forced to find ways to make money. Joe Louis wrestled, Jake LaMotta did stand-up, and Mike Tyson copped. At $99 a ticket, it's a living.

He seems happy. He is down 140 pounds from his self-described "fat cokehead" high of 370. And he's in a forgiving mood, of everybody but himself.

"I'm all dressed up tonight," he said, open-palmed, "but I'm still an animal underneath."

A Vegas show with an animal that could still bite?

It'll sell.