1. Greg Hardy
Former NFL star Greg Hardy was disqualified during his debut match in the UFC against Allen Crowder at UFC Fight Night 143. Hardy landed an illegal knee attack on Crowder’s head when he was grounded. He was then immediately disqualified.
— Bulgogi Jones (@Hamderlei) January 20, 2019
2. Michael Pereira
Big mistake for Michael Pereira because he was dominating the whole fight. The bout took place at UFC Fight Night 167 against Diego Sanchez. When dominating the fight, Pereira accidentally landed an illegal knee on Sanchez’s head.
— ESPN MMA (@espnmma) February 16, 2020
3. Anthony Johnson
Anthony Johnson was disqualified during his fight against Josh Koscheck. He wasn’t immediately disqualified, instead, he was disqualified after Koscheck said he could not continue fighting due to an illegal strike.
4. Jon Jones
Jon Jones was disqualified at the UFC – The Ultimate Fighter 10 Finale back in 2009. He was fighting Matt Hamill. It was his one and only defeat in his UFC career. Even though, he wasn’t actually defeated. He was disqualified after he used the banned technique referred to as 12-6 elbow.
5. Petr Yan
The former bantamweight champion Petr Yan lost due to disqualification when he fought Aljamain Sterling at UFC 259 during a bantamweight title fight. Petr Yan kneed Sterling while Sterling’s right knee was on the ground. This means Sterling was in a grounded position and can not be kneed to the head. This caused Petr Yan to be disqualified and Aljamain Sterling became the champion.