After submitting McGregor (21-4) in the fourth round, Nurmagomedov (27-0) left the Octagon to confront McGregor's corner. McGregor also headed in that direction, and ended up in an altercation with several members of Nurmagomedov's team inside the cage.
At this point, what do we know about what happened in the aftermath of UFC 229? And where do things go from here? ESPN breaks it down.
Why did it happen?
Because Nurmagomedov was angry. Really, really angry.
McGregor has a history of getting under the skin of his opponents, but his verbal attacks on Nurmagomedov were a shade "darker" than usual (to steal a description used by UFC president Dana White after their first news conference).
McGregor called Nurmagomedov's father, Abdulmanap, a "coward" and made a vague remark about what might happen to Nurmagomedov's family if he pulled out of the fight for any reason.
Of course, he also physically attacked a bus Nurmagomedov was on back in April, in Brooklyn. There were many layers to this, and we haven't even mentioned the competitive angle to the fight itself, the fact it was between the two top lightweights in the world.
"What about he talk about my religion, he talk about my country, he talk about my father, he come to Brooklyn and he broke bus, almost kill couple people," Nurmagomedov said after the fight. "What about this? Why people talk about me jumping over cage? Why people talk about this?"
McGregor's head coach John Kavanagh told the Joe Rogan Experience podcast on Monday he can "stretch myself to understand his reaction."
Who was involved?
After Nurmagomedov jumped out of the Octagon, he went straight for McGregor's teammate and Bellator welterweight Dillon Danis. Danis is a 25-year-old New York native who has helped train McGregor's jiu-jitsu and actually paid his $50,000 bond in April after he was arrested for the bus incident.
Inside the cage, Nurmagomedov's cousin, whom he refers to as his brother, Abubakar Nurmagomedov ran toward McGregor's corner and started to climb the fence. McGregor appeared to hit him with a punch, which prompted him to climb off the fence and briefly wrestle with McGregor. Nurmagomedov is currently signed to the Professional Fighters League.
Another member of Nurmagomedov's camp, Zubaira Tukhugov, was seen briefly engaging McGregor inside the Octagon. Tukhugov later posted a video to social media saying he "slapped [McGregor] as promised," according to a translation by BloodyElbow.com. Tukhugov is signed to the UFC and is supposed to fight McGregor's teammate Artem Lobov at the end of the month. The status of that fight is uncertain.
What happens now?
There are currently no known criminal charges pending, as "no one involved wished to press charges," according to a statement released by Las Vegas police to MMAFighting.com.
The Nevada State Athletic Commission has withheld Nurmagomedov's entire $2 million paycheck, in expectation of a pending complaint against him. McGregor received his paycheck on fight night, however NSAC chairman Anthony Marnell told ESPN on Monday the commission intends to file against him as well, after reviewing film that was not immediately available. Marnell also said the commission is looking into possible avenues to punish other individuals, beyond the fighters.
Both Nurmagomedov and McGregor are facing potential fines and suspensions. Nurmagomedov is still the UFC's lightweight champion, however White said if he is suspended for a lengthy amount of time, the promotion will consider stripping him.