Conor McGregor 's 2017 crossover fight against ring legend Floyd Mayweather has been branded "fake" by Khabib Nurmagomedov.
In a fight that drew the attention of all fight fans, former two-weight UFC champion McGregor stepped into the ring for the first time as a professional against 49-0 Mayweather.
After winning more rounds than many expected, McGregor was eventually stopped by Mayweather in the 10th session and neither man has boxed professionally since.
The crossover fight was a huge success on pay-per-view selling 4.3million buys, the second largest of all-time.
Retired UFC star Nurmagomedov admitted the crossover bout was a "historic event", but likened it to a sparring match.
"Not many people care about this fight," Nurmagomedov told the Full Send podcast.
"It was a historical event because of an MMA champion vs boxing champion but many people don't even remember what happened inside the fight.
"It was just like sparring fight and for me, it was not real fight because this guy [McGregor] not a real boxer. For me it was more like a fake fight."
Nurmagomedov has a fierce rivalry with McGregor, with a mass brawl unfolding outside of the octagon after their title fight in 2018 in which 'The Eagle' won by submission.
And the Russian thinks whilst McGregor's fight with Mayweather was "fake", their rivalry and grudge match at UFC 229 was exactly the opposite.
"This is just my opinion. Maybe, maybe not... Then, what was between us, it was real. Everything what happened before the fight, inside the fight, after the fight."
McGregor pressed for a rematch with Nurmagomedov after the fight, but the Russian would fight just twice more before retiring from MMA.
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After the death of his father and coach in 2020, Nurmagomedov promised his mother he would not fight again after his UFC 254 bout with Justin Gaethje.
An emotional Nurmagomedov retired in the cage after submitting Gaethje and 'The Eagle' admitted he kept it a secret from everybody close to him.
"That time, I know it's going to be my last fight but I didn't tell anybody. People talk about like 'oh this guy can beat Khabib' but I don't care about this," he continued.
"I don't care, when I fought Conor, [Rafael] Dos Anjos, [Dustin] Poirier, [Edson] Barboza and Justin Gaethje. They was always talking about 'oh maybe this guy can stop him'.
"Then when I come to the cage and I feel my opponents I'm like 'come on guys, this guy is not on my level.'"