Fists flew both inside and outside the octagon Saturday as a post-fight brawl marred a dominant performance by Khabib Nurmagomedov over Conor McGregor at the highly anticipated UFC 229 in Las Vegas.

In the aftermath, three members of Nurmagomedov's entourage were arrested, but later released because McGregor declined to press charges, according to Bleacher Report, which cited information from Dana White, president of Ultimate Fighting Championship.

Nurmagomedov, undefeated at 27-0, and the UFC’s lightweight champion at 155 pounds, won the fight in Round 4 by subduing McGregor at the 3:03 mark.

Right afterward, Nurmagomedov, of Russia, jumped out of the octagon and went after one of McGregor’s trainers and threw his mouthpiece -- and a brawl ensued.

The trainers responded with taunts and climbed over the octagon and fought Dillon Danis, a Bellator welterweight who trains with McGregor.

An unidentified man then climbed into the octagon and punched a weary McGregor, of Dublin, who was still recovering from the fight.

“I don’t even know what to say right now,” White said afterward. “I’m just disgusted and sick over it. ... We had so much security and (police) here. I didn’t see that one coming.”

McGregor will be paid but not Nurmagomedov, per an investigation by the Nevada State Athletic Commission.

Nurmagomedov and McGregor, 21-4, left the ring before the winner of the fight was announced. White feared that putting the belt on Nurmagomedov would further rile the crowd.

The fight was marred by bad blood between the two that goes back to when McGregor threw a handtruck at a bus carrying Nurmagomedov last April at the Barclays Center in Brooklyn, N.Y. He had been upset at an earlier confrontation between Nurmagomedov and a member of his team.

McGregor was arrested following the incident.

The incident led to major hostilities between the two camps during the buildup to Saturday's bout.

Four security guards separated the two during the fighter introductions Saturday and both refused to touch gloves.

Daniel Cormier, a friend of Nurmagomedov's, took to Twitter to give his thoughts on the melee.

It was McGregor’s first fight since winning the lightweight championship in 2016. He forayed into boxing in August 2017 when he was knocked out by Floyd Mayweather Jr.

During his absence from the UFC, the organization stripped him of his lightweight title for inactivity.

The Associated Press contributed to this report.