Nurmagomedov beat McGregor via submission in the fourth round of a contest marred by pre and post-fight controversy.
McGregor was accused of insulting his opponent’s family, country and religion in the build-up to the fight.
And afterwards, Khabib launched himself in to the crowd to attack McGregor’s corner.
Yet the two of them may have actually been friends back ijust four years ago.
A conversation between the pair when Khabib was promoting a range of t-shirts in September 2014 has re-emerged on Twitter.
The Russian tweeted his then-pal, saying: “Hey Conor, I’m in Vegas when you come let me know, I want you gave me this shirt.”
The Irishman replied: “Let’s do it brother! I fly out to Vegas tomorrow!! Hit me up and we can train.”
All that was a far cry from the chaos in Las Vegas on Sunday.
After Khabib retained the lightweight championship, he lost his temper and vaulted out of the octagon.
He took aim at McGregor’s team and sparked a mass brawl that saw three of his own entourage arrested.
The 30-year-old was not presented with the belt in the octagon as a result and the Nevada State Athletic Commission are currently withholding his payment for the fight while they conduct a review.
The champion was quick to apologise for his behaviour but claimed he had been provoked by his rivals’ pre-fight antics, which started back in April when the Irishman attacked Khabib’s team bus in New York.
He said: “First of all I want to say sorry to Nevada Athletic Commission and second to Vegas. I know this is not my best side. I’m a human being.
“But I don’t understand how people can talk about how I jump on the cage. He talked about my religion, he talked about my country, he talked about my father.
“He came to Brooklyn and he broke a bus, he almost killed a couple of people. What about this s***? Why do people talk about me jumping over the cage? I don’t understand.
“This is a respectful sport, not a trash-talking sport. I want to change the game, you cannot talk about religion, about nationality.”
Meanwhile, McGregor has hinted at a stunning grudge rematch. He responded on Twitter, saying: “Good knock. Looking forward to the rematch.”