Kash Ali was disqualified for biting British rival David Price during the fifth round of their heavyweight clash at the M&S Bank Arena in Liverpool.
After Price had connected with a strong counter-punch right hand on the previously undefeated Ali, both men ended up grappling.
As the pair, who used to be sparring partners, fell to the canvas, Ali landed on top of the Liverpool fighter and subsequently bit him under the ribs.
After Price showed referee Mark Lyson the bite marks, Ali - docked a point in the third round after previously being warned for punching to the back of the head - was swiftly disqualified.
The result saw the Birmingham fighter suffer a first defeat after 17 contests, and also had his purse withheld. As he left the ring, several drinks were thrown from the crowd.
There had been little love lost between the rival fighters during the build-up, which included an expletive-laden exchange from Price at a pre-fight press call.
Speaking in the ring, the fight broadcast on Sky Sports, Price was asked about a rematch, but he said: "I don't want to share a ring with an animal like that again."
Former world cruiserweight champion Tony Bellew branded Ali "a disgrace" and called for him to be banned.