Tony Bellew has slammed David Haye for threatening to put him in hospital when they meet next year.
The two Britons clashed at a heated press conference on Wednesday and amid the arguments Haye told Bellew: "Let's see who's around your hospital bed on March 4. His life is on the line."
The pair then scuffled as they posed for photographs, with Haye hitting Bellew who shoved him back.
Bellew, 34, was more critical of Haye's comments, with Germany-based super-middleweight Eduard Gutknecht still in a coma at a London hospital following a fight against George Groves on Nov. 18.
British middleweight Nick Blackwell, meanwhile, needed surgery to reduce swelling on his brain after being injured in a sparring session last week.
Blackwell had retired from boxing after being placed in an induced coma following a brain injury sustained in a fight against Chris Eubank Jr. in March.
"I'm disgusted in David throwing a punch like that and some of the things he said," Bellew told reporters.
"He got too close and I just pushed him off and he caught me with a left hook to the head. He was a bit jumpy and nervous.
"Some of the things he said, saying you are going to a hospital bed while a boxer is in a coma just up the road, you just don't brag about things like that.
"We don't need clowns like him saying I'm going to leave you in hospital.
"I thought it was distasteful saying that because there are boxers in comas at the moment. There's a line and he crossed it.
"I've got previous so I'm not perfect. But he's just not a nice person. He's forgot where he's come from."
Bellew will step up to heavyweight after one defence of his WBC world cruiserweight title and is not ruling out a permanent switch to the division if he beats Haye, a former world heavyweight and cruiserweight champion.
"If I knock out David Haye there's a new sheriff in town," Bellew told reporters.
"I would love to be a two-weight world champion.
"I'm 16 stone right now. I will eat as clean as possible and I will try and stay off the KFC. I've got no goal in mind when it comes to what weight I will come in at, but David will come in light because if he's slower than me then he's in a world of trouble. I'm harder to hit than I look."
Super-middleweight Groves, who trains at the same south London gym as Haye, has launched a fundraising appeal on behalf of Germany-based Gutknecht, who is being treated at St Mary's Hospital in west London.