McGregor lost to Nurmagomedov last night, tapping out in the fourth round after his Russian opponent had got him in a headlock.
What happened next, though, has sent shockwaves around both the sporting and UFC world.
Conor McGregor appeared to throw a punch at a member of Nurmagomedov’s coaching team, before the Russian responded by jumping into the crowd.
Fans were also seen brawling behind the scenes as tempers in Las Vegas reached boiling point.
And celebrities Sofia Richie and Scott Disick were among the famous faces rushed out.
Richie, an American model, took to social media to claim she was forced from the fight.
And her boyfriend Disick was with her when it happened.
She put on Instagram at the UFC fight: “So the night ended in us getting rushed out.
“Of course I attend the fight that ends in a riot.”
Nurmagomedov apologised for what happened after defeating McGregor, saying: “First of all I want to say sorry to (Nevada State) Athletic Commission, Nevada, sorry to Vegas.
“I know this is not my best side.
“This is not my best side. I am human being.”
But he then did try to justify his actions, calling out McGregor for what he perceived to be racist comments made beforehand.
“I not understand how people can talk about I jump on cage,” Nurmagomedov said.
“He talk about my religion, he talk about my country, he talk about my father.
“He come to Brooklyn, and he broke bus. He almost kill a couple people, worry about this (expletive).
“Why people talk about I jump on cage? Why people still talk about this? I no understand.
“My California seven years. Everybody know who I am. All my friends. Everybody who know me, they know who I am.”