It was a night of shame for the UFC as fighting between fans broke out after Conor McGregor's defeat to Khabib Nurmagomedov - just minutes after mass brawls in the Octagon marred the Russian's in the T-Mobile Arena in Las Vegas.
Nurmagomedov submitted McGregor in the fourth round and their bout ended in disgusting scenes when the Russian scaled the cage and appeared to attack someone from McGregor's team.
A prone McGregor was then seemingly attacked by someone from Nurmagomedov's camp as the bad blood that has been building up ahead of this fight came to a head.
UFC chief Dana White confirmed later that three of Nurmagomedov's team were arrested and taken to jail but were released later because McGregor refused to press charges.
Footage has now emerged of vicious fighting outside the arena.
The video, posted on Twitter, shows what appears to be Irish and Russian fans clashing.
One Irish fan is knocked out and left with blood streaming from his face during the disturbing incident.