One of the most hotly anticipated bouts in UFC history has devolved into scenes of utter chaos.
Khabib Nurmagomedov's convincing fourth-round submission win over Conor McGregor at UFC 229 was instantly tarnished as the Russian clashed with the Irishman's team in a wild brawl outside the Octagon, while his own team attacked McGregor inside it.
Clearly overcome with emotion after McGregor tapped to a rear-naked choke hold, Nurmagomedov stood over his vanquished opponent and screamed in his face, then walked over to the opposite corner, leapt the fence and began trading shots with McGregor's training partner, Dillon Danis.
Meanwhile, members of Nurmagomedov's team made their way inside the Octagon and swarmed an exhausted McGregor, landing at least two heavy punches.
Police came to McGregor's aid and whisked him down the tunnel into the safety of the bowels of Las Vegas' T-Mobile Arena.
Nurmagomedov eventually returned to the Octagon where he began to plead for the lightweight belt he'd just defended.
UFC president, Dana White, refused to put it around Nurmagomedov's waist in fear of further inciting an already riled crowd. The Russian was then also escorted out of the arena, pelted by water bottles from the angry Irish faithful.
"Khabib jumped over the cage going after one of Conor’s guys, who I guess was talking trash to him, and all hell broke loose," said White in the post-fight show.
"I don’t even know what to say right now. I’m just disgusted and sick over it.
"The governor was here tonight and he went running out of the building. This isn't good. He [Khabib] is in a lot of trouble."
White later confirmed that three members of Nurmagomedov's team had been arrested and taken to jail, and that McGregor was unharmed - apart from his wounded pride.
"I just talked to [McGregor] and he’s okay. He's upset about the fight — not about the fight after the fight.
He also expects charges to be laid against Nurmagomedov, which could have huge implications for his Visa to enter the US and puts his future with the promotion in jeopardy.
There had been plenty of bad blood between the two fighters in the lead up to the bout, dating back to McGregor's frenzied attack on a bus which Nurmagomedov was aboard in Brooklyn six months ago.
That was a retaliation to an earlier confrontation between Nurmgaomedov and McGregor's longtime friend and training partner, Artem Lobov.
The incident has added the most sour of after-tastes to what should've been a crowning moment for "The Eagle", who kept his undefeated record in tact with a comprehensive win over the returning McGregor.
The grappling phenomenon wasted no time inflciting his suffocating ground game on McGregor, and while the Irishman was at times valiant in defense, he was ultimately overwhelmed by Nurmagomedov's relentless pressure.
Nurmagomedov also showed signs of his improving striking abilities, sending McGregor to the mat with a heavy overhand right during a second round in which he manhandled his opponent.
But what could have been the conception of a legendary rivalry- a series of fights for the ages - may have simply been a premature end to a potentially great champion's UFC career.
The stage was perfectly set for the main event by some fantastic undercard fights, highlighted by a jaw-dropping bout between lightweights Tony Ferguson and Anthony Pettis.
The two gifted strikers exchanged an endless variety of shots in a breathless, blood-soaked battle that ended in Ferguson's favour, after Pettis was forced to throw in the towel with a broken hand at the end of the second round.
In other results, Derrick Lewis fought back to earn a knock-out win over Alexander Volkov, while Dominick Reyes scored a unanimous decision victory over Ovince St. Preux.