Heavyweight action brought more than 10,000 people to Madison Square Garden in the middle of a blizzard last Saturday night. I was one of them. We watched two top-20 heavyweights in Joe Mesi and Monte Barrett go at it over 10 tough rounds. Then, in the main event, we watched top-three heavyweight Vitali Klitschko cement his claim that he is indeed Lennox Lewis' top challenger, by destroying top-10 contender Kirk Johnson in two rounds.

Vitali's emergence as Lennox's top contender and potential pay-per-view superfight adversary is the big story. Having established that, I will now proceed to bury the lead.

First fight first. Mesi dominated Barrett over the first six frames. His superior technique - shorter left hook and straighter right hand - had Barrett in bad trouble several times over those first 18 minutes. And then a funny thing happened on the way to his second commanding performance against a name heavyweight (the first was Mesi's devastating first-round blowout of DaVaryll Williamson) in the last 10 weeks. Barrett, who came in against Mesi in tremendous shape (more later about an underdog making the most of an opportunity by getting into the best shape he can), dropped the charging "Baby Joe" with a left hook. Mesi got up, but the momentum of the fight was permanently changed. Barrett won the last four rounds.

Mesi's amateur background and the deliberate pace of his development in the pros have thus far resulted in a fighter whose technique is superior to the third- and even second-tier opposition that he has faced. But against that second tier - a shot David Izon, a dangerous and athletic but amateurish and weak-chinned DaVaryll Williamson, and an experienced but sloppy Monte Barrett - Mesi has experienced problems and exhibited some serious flaws. One of those flaws in particular almost led to the undefeated Buffaloan's undoing at the Garden. Mesi blew out Williamson so quickly that these flaws did not have time to show themselves, but against Izon and especially Barrett they were prominently on display.

Izon's loss to Mesi was sandwiched between losses to Fres Oquendo and Al Cole. Izon was dominated and dispatched in three rounds by Oquendo and decisioned by Cole (who himself does not take much credit for beating an over-the-hill Izon). Yet Mesi, who dominated Izon over the first several rounds of their fight, seemed gassed by the middle rounds and even seemed affected by several shots from Izon, who, after a tough career, has very little boxing left in him.

Against Barrett, Mesi also dominated the early going, but was breathing heavily through his mouth in between rounds by the middle of the fight. Mesi appears extremely focused - to the point of being unable to relax - in fights against name opponents. He therefore boxes carefully and controls the action early, but is fatigued by the middle rounds and struggles later on in the fight. This dynamic, not prominently on display against Izon, was pronounced against Barrett.

Mesi admitted in his post-fight interview on Saturday that he can go 10-12 rounds in the gym easily, but that going 10 rounds in an actual pro fight is much more difficult. In other words, the pressure of the moment causes heightened tension, which leads to premature fatigue. The good news for Mesi is that relaxing - and for that matter turning one-twos into legitimate combinations by finishing with his left hook - are acquirable traits, that is, he can learn to do them. The bad news is that while he has good punching power and solid technique, his hand and foot speed are average and it does not appear to take much to shake him up - his chin is suspect.

Okay, on to the real event of the evening...

Kirk Johnson came into his fight against Vitali Klitschko woefully out of shape - at the very least, his physique was less than aesthetically pleasing. And Kirk - who is a very nice guy and a good fighter - is one of these fat heavyweights who bemoans the expectation that he come into fights looking as though he's done some roadwork. So he comes in against Vitali at an official weight of 260.

Now, Kirk is a guy who, when he weighed in around 235, looked like he could afford to lose a few pounds. And while he is naturally gifted - he is relatively fast, mobile and has real punching power - and fairly skilled for a heavyweight, he is not the second coming of Muhammad Ali. Kirk is not so good that he can afford to show up fat against an opponent as good as Klitschko. Even Ali, towards the end of his career, suffered when he came in undertrained against top opponents.

This is now the second major opportunity in the last year and a half that Kirk has squandered. The first came against John Ruiz in July of last year. Johnson is more talented than Ruiz, but going into that fight I felt that Ruiz, who found ways to compete if not always beat Evander Holyfield, would be resourceful enough to get by Johnson. He was. Kirk self-destructed against Ruiz, in the first place entering the fight in obviously less than perfect shape, and then going on to lose a close contest on a foul. Kirk lost because he continued throwing borderline body shots and Ruiz exaggerated the effects of the ostensible low blows until the ref disqualified Johnson.

But even though Kirk controversially lost a fight he may have deserved to be winning, it was not as if he had the fight won and was simply cheated. Ruiz floored him with the same sneaky right he used to do drop Evander. It was unclear at the moment of the stoppage that Kirk would survive the fight, let alone win it.

Against Klitschko, Kirk offered next to nothing. He looked to counter Vitali's straight right hand with his left hook. Generally, because the shortest distance between two points is a straight line, in a battle between the straight right and the hook, the straight right wins. It sure did this time.

Vitali looked excellent. He entered the ring totally focused and obviously in shape. Sizing up Kirk's lack of preparedness he seized the moment: rather than passively boxing and taking a safety-first attitude, he actively pursued and quickly imposed himself on his much shorter opponent. In so doing he not only got the win, but leapfrogged to the head of the heavyweight class in terms of the public's perception, and maybe even officially ahead of all the contenders ahead of him in the Ring Magazine rankings.

Certainly there is now a very compelling argument that Vitali is No. 1. Chris Byrd was lucky to escape with a win against Fres Oquendo. Corrie Sanders knocked out Wladimir Klitschko, and that was a huge win, but it was his only win of note in recent years.

Viatli, in his last two fights, won four of the first six rounds against the heavyweight champion of the world, before being stopped on cuts - over his vociferous objections - and then just destroyed a top 10 heavyweight in two rounds.

There are good arguments for keeping Chris Byrd and Corrie Sanders ahead of Vitali in the ratings, but it is probably a moot point. There is no clamor for Byrd or Sanders to get a shot a Lewis. It is undeniable that at this moment, Vitali is the contender who matters. He is the one the people want to see in against Lennox, and if Lennox decides to retire, Vitali will be the heir apparent. No claim to the heavyweight throne, reasonable or otherwise, will be considered legitimate, or at least complete, until the fighter making that claim gets in there with Vitali Klitschko, the No. 1 heavyweight contender on the planet.

Max Kellerman is a studio analyst for ESPN2's "Friday Night Fights" and the host of the show "Around The Horn."