How the mighty have fallen. "The Iceman" Chuck Liddell is now 0-2 against Quinton "Rampage" Jackson.

Make that Quinton "Rampage" Jackson, UFC light heavyweight champion.

Jackson tagged Liddell with a right hook that dropped him to the mat, and followed up with a series of punches that knocked out Liddell at 1:53 of Round 1 in the latest in a series of main-event upsets in UFC this year.

Liddell (20-4 overall, 15-3 UFC) was gracious, if disappointed, after the loss.

"You know, I got caught," Liddell said. "I made a mistake and got caught."

Jackson (27-6 overall, 2-0 UFC) came into this title fight as the only man to ever defeat Liddell and not lose to him in a subsequent rematch. Liddell looked forward to avenging the 2003 loss at UFC 71, but instead was defeated even faster this time around.

Now Liddell will have two reasons to pursue Jackson. Jackson used to only have Liddell's number. Now, he also has his title belt.

"I always want a rematch," Liddell said. "We'll see what they'll do."

After knocking out the UFC's hottest star -- again -- "Rampage" was all smiles, especially when UFC interviewer Joe Rogan introduced him as the new champion.

"Man, that sounds good," Jackson said. He also did not hesitate to agree to a possible rematch.

"Me and Chuck can do it again. I agree with Chuck. Let's do it again," Jackson said.

In a week highlighted by unprecedented mainstream media coverage of UFC -- including a Sports Illustrated cover story and coverage on various ESPN programs -- UFC 71 had a diverse cross-section of pop culture celebrities seated in the crowd. UFC cameras caught rapper Lil' Jon mugging in the audience. Actors Adam Sandler, Kevin James and David Spade were also there. Representing the sporting world were the likes of Rob Dibble and tennis legends Andre Agassi and Steffi Graf.

Agassi made it clear who he was rooting for prior to the main event.

"I gotta go with Chuck. How do you not? The guy has sandbags for fists," Agassi told Rogan during the broadcast.

The trouble is, so does Quinton Jackson. The two were cautious in the early going, with Liddell circling backward and trying to lure Jackson into chasing him -- a strategy Liddell has used with success in many fights. Jackson didn't bite. By the time the two men got close enough for an exchange of fists, neither fighter looked fazed by the strikes.

Seconds later, Jackson threw a looping right hook that put Liddell on the canvas. Still coherent, Liddell defended himself briefly before another right hand flatted him out, and the official stepped in to end the fight.

Proclaiming that he stepped up his training, Jackson promised he would not be a flash-in-the-pan UFC champion.

"I'm gonna be this way for a while," Jackson said.

As a surprise hyped by UFC days before UFC 71, Dan Henderson -- a double-weight-class champion for Pride FC, which UFC's owners purchased this year -- entered the Octagon during Jackson's post-fight interview holding the Pride middleweight title belt on one shoulder, and the Pride light heavyweight title belt on his other shoulder.

It was easy to see where this was going, as Jackson smiled and hugged his friend.

"Don't tell me I gotta whoop on my friends, now," Jackson joked to Rogan.

Henderson and Jackson had a friendly exchange, both indicating that they would fight anyone -- even a friend -- if the fight could draw big money. Jackson motioned in Liddell's direction.

"I wanna be like him," Jackson said. "He's a big baller. Have you seen his crib?"

The UFC 71 undercard proved worth the price of admission by itself.

If ever there was a fight that displayed why the sport is called mixed martial arts, Karo Parisyan and Josh Burkman had it on Saturday. The fighters put on a clinic of fists, kicks, grappling, judo throws and submission attempts en route to Parisyan beating Burkman via a unanimous judges' decision.

Both men came out swinging in the first round, but soon began trying for takedowns and throws. Parisyan nailed Burkman with a textbook Judo throw late in the round and worked for a kimura submission to end a busy first round.

Parisyan picked up the pace in the second round as Burkman began dropping his arms and looking at the clock, apparently losing steam. Parisyan failed to put away Burkman, but established control of the pace of the fight, and was able to strike with success. Burkman showed signs of life in the third round, but it wasn't enough to overcome the lead Parisyan had built.

Terry Martin defeated Ivan Salaverry quickly, and then issued a challenge to UFC middleweight champion Anderson Silva when it was over.

Martin beat Salaverry at 2:04 of Round 1 after grabbing him in a waistlock from behind and slamming him onto his left shoulder, face first. Martin followed up with fists for the referee stoppage.

In a spectacular -- if short -- slugfest, Houston "The Assassin" Alexander made his UFC debut by shocking Keith Jardine in 48 seconds with a vicious knockout.

Jardine appeared to have stunned Alexander with a punch early, but Alexander fired back with a frenzy of punches that forced Jardine to retreat backward into the cage. Alexander dropped Jardine to his knees with a right uppercut, and as Jardine rose to his feet again, another right uppercut knocked out "The Dean of Mean" and gave Alexander an unexpected victory.

"That's real punching power right there," a jubilant Alexander said after the win.

Two former cast members of The Ultimate Fighter squared off as Kalib Starnes earned a hard-fought unanimous decision over Chris "The Crippler" Leben. Starnes and Leben kept the fight standing for the vast majority of the three rounds, with Starnes doing slightly more damage to win the judges decision. The final round ended with the fighters exchanging punches from the ground, and the audience gave them a standing ovation as the round came to a close.

Complete results from Saturday's UFC 71 in Las Vegas:

1. Quinton "Rampage" Jackson defeated UFC light heavyweight champion Chuck Liddell via knockout due to strikes at 1:53 of Round 1 to win the title.
2. Karo "The Heat" Parisyan defeated Josh Burkman via unanimous decision after three rounds.
3. Terry Martin defeated Ivan Salaverry via TKO due to strikes at 2:04 of Round 1.
4. Houston Alexander defeated Keith Jardine via KO (right uppercut) at the 48-second mark of Round 1.
5. Kalib Starnes defeated Chris Leben via unanimous decision after three rounds.
6. Thiago Silva defeated James Irvin via TKO due to referee stoppage at 1:06 of Round 1.
7. Alan Belcher defeated Sean Salmon via submission to a guillotine choke at the 53-second mark of Round 1.
8. Din Thomas defeated Jeremy Stephens via submission to an armbar at 2:44 of Round 2.
9. Wilson Gouviea defeated Carmelo Marrero via submission to a guillotine choke at 3:06 of Round 1.