Anthony Joshua threatened to throw a chair across the face of Daniel Dubois as the two heavyweights were restrained by security during a heated interview.
Dubois, 26, will defend the IBF world title against his fellow Briton at Wembley Stadium on 21 September.
Broadcaster Dazn released a short clip of the interview, recorded before Thursday’s news conference, on social media.
Two-time world champion Joshua, 34, said he was “ready to fight”, to which Dubois replied: “Let’s go. If he wants to swing, let’s go now.”
A visibly annoyed Joshua told Dubois not to disrespect him, adding: “I’ll throw this [expletive] chair across your face
Dubois has been a somewhat reserved character in the past, but the Londoner refused to back down.
“You don’t intimidate me, who do you think you are?”, he asked Joshua.
Both men stood up from their chairs.
Security intervened as Joshua called Dubois a “little boy” and promoters Eddie Hearn and Frank Warren attempted to defuse the situation.
Queensberry’s Warren then asked the production team to cut the interview short.
Dubois has won his past two fights, stopping Jarrell Miller in December and Filip Hrgovic this month.
He was elevated to world champion status after undisputed champion Oleksandr Usyk – who is set to contest a rematch with Tyson Fury in December – vacated the belt on Tuesday.
Joshua is on a four-fight winning streak and has three stoppages in his past three bouts.
The winner will put themselves in prime position to fight the winner of Usyk-Fury.
