4. Khabib Nurmagamedov
Khabib and Conor McGregor had one of the most toxic rivalries in UFC history. The pair finally fought in 2018 at UFC 229. The Russian lightweight champion successfully defended his title against “The Notorious” with a fourth-round submission. However, the fight didn’t end there. Infuriated and emotional over events that led up to the fight, Khabib jumped out of the cage and attacked McGregor’s team.

This ignited an entire brawl as members of Khabib’s team entered the cage and tried to attack McGregor. Chaos erupted within seconds after tantrums became an all-out war. In the end, the pair received fines and suspensions from the UFC. It was an infamous event that sealed its place in MMA folklore. Meanwhile, this rivalry continues to rumble.