UFC superstar Conor McGregor was overwhelmed by the words of respect that unexpectedly came from former undisputed heavyweight champion Mike Tyson.

Tyson threw high praise in the direction of McGregor, for his boxing performance against five division world champion Floyd Mayweather.

When the contest started, McGregor was able to do well in the early rounds - but he faded, with Mayweather breaking him down for a ten round stoppage.

Critics have long claimed that Mayweather intentionally carried McGregor in the early rounds, in order to make the fight more entertaining for the millions who purchased their high priced pay-per-view event.

At the time of the fight, Mayweather was 40-years-old and coming back from a two year layoff.

Tyson was very impressed with McGregor's ability to step in a boxing ring for the first time and last ten rounds with a fighter who many regard as one of the best boxers of all-time.

“Listen, (it was a spectacle) but this is where it’s not a spectacle - it’s a spectacle but this is where it’s not: he never really had a boxing match in his life, right? He didn’t have a boxing match (and) he went 10 rounds with the greatest fighter in the last 100 years of boxing,” Tyson said on his Hotboxin' podcast.

“Think about that. . . He went 10 rounds, scored punches on the greatest fighter in the last 100 years. Did he do something? Did he accomplish something? People ain’t looking . . . but look what he had to fight against and look what he did when he fought against it. Imagine a guy never had a boxing match and he’s fighting boxing with me. He goes 10 rounds and he’s fighting me and we’re fighting. Imagine if he did (go 10 rounds) and we’re fighting and I’m doing my thing. That’s a bad motherf--ker.

"First fight, 10 rounds with the champ, the best champ in the last 50 years or something like that. Pfft, that’s the winner of the fight! That’s the winner. This should’ve been a one round, two round fight. Floyd should’ve took it easy, (but) he had to sweat, he had to fight him. He had to fight somebody who was throwing back.”

When Tyson's praise reached the ears of McGregor - he promised the heavyweight great that he's going to beat Mayweather in the rematch - should it ever happen.

While Mayweather claims that he's not planning to fight again, McGregor believes the rematch will eventually happen.

"Thank you Mike, and just know that for the inevitable rematch, with the knowledge I now hold of Floyd’s style, plus under the tutelage of my old school boxing coach, I will crack the puzzle, and I will beat Floyd. I promise my life on it," McGregor stated.