Max Kellerman, who works for HBO Sports and ESPN, admits he was wrong about UFC superstar Conor McGregor and his ability to perform against five division champion Floyd Mayweather Jr.

McGregor made his professional boxing debut against Mayweather on Saturday night at the T-Mobile Arena in Las Vegas.

Mayweather, 40 years old, was coming back from a two year retirement. He walked away from the sport in September 2015. The contest took place at the junior middleweight limit of 154-pounds, with 8-ounce gloves being used.

In a previous interview, Kellerman gave McGregor a zero shot to beat even a 60 year old version of Mayweather.

McGregor made things interesting and appeared to win the first three rounds, but eventually fell victim to exhaustion and was stopped in the tenth round.

"They’re in a boxing ring. Conor has a zero percent chance. Precisely zero percent. They’re in a boxing ring. Conor McGregor, there’s no universe in which he can win," Kellerman told Desus & Mero.

"I mean, even the thought of it - if Conor McGregor was like a decorated amateur and they built him up, you know? He had a four-round fight, a six-round fight, this...then after fifteen fights he was like 14-1, and then fought a contender - even if he lost to the contender, right? But at least he held his own over ten rounds, it usually takes about 5 or 6 years to build a guy like that out of the amateurs."

"Then he would have a chance to win a round against someone half as good as Floyd Mayweather. But you’re gonna turn pro after not being in a boxing ring competitively for how many years? And fight one of the best pure boxers of all time? It doesn’t matter that he’s 40 or whatever. If [Mayweather] was 60 it wouldn’t matter."

But after watching Saturday's encounter, Kellerman has a different take on McGregor and the fight.

"I want to start out by saying Conor McGregor deserves enormous credit. He is an exceptional fighter, an exceptional fighter. Even among champions he stands out. And what stood out to me for Conor the boxer....... first of all he is making his pro debut against one of the best fighters ever. I’m going to get to the age thing in a second, and he’s, early on, doing enough to stay in the fight. That’s amazing. Even the fact that he went ten rounds in his pro debut is amazing," Kellerman said on First Take.

"And how is he able to have any success at all? He is not only incredibly determined with a huge heart and athletic. By the way, when you see one fighter get around another fighter as Conor did to Floyd and actually step behind him, that means his feet are faster, it means he’s younger, or at least more athletic – that’s a huge thing. Conor is athletic, energetic, determined, his preparation is clearly there, but more than anything Stephen A. - it’s his fighting brain.

“Conor McGregor, as most great fighters have, has an extremely high fighting IQ. It’s the reason that he didn’t really hit Mayweather with anything hard. He didn’t load up on any punches, he had the uppercut in the first round. I know I said that he would not even lay a glove on Mayweather, not a clean punch, and I have a lot of people on Twitter saying he landed 111 punches – no he didn’t. But Conor did land about ten or a dozen punches over the course of ten rounds, which is actually more than most fighters land cleanly against Mayweather."