Anthony Joshua has labelled Lennox Lewis 'a clown' after he criticised his preparation for this summer's shock defeat by Andy Ruiz Jr in New York.
Lewis is Britain's last undisputed heavyweight champion, and tweeted after Joshua's total knockout loss: 'I can't look at that fight and agree that AJ was fully prepared'.
Joshua has responded by claiming that he and Lewis 'are cut from a different cloth'.
'Lennox is a clown. I don't respect Lennox,' Joshua said on Sky Sports documentary AJ: The Untold Truth.
'Me and Lennox are not the same. My legacy is to sit back and enjoy the younger generation coming up, and not to be involved. Just to appreciate what it takes to get there.
'Lennox isn't like that.'
Joshua is set to take on Ruiz in the ring again in Saudi Arabia on December 7.
The IBF, WBA and WBO heavyweight titles will be at stake in the showdown.