Tony Bellew believes he will force David Haye to throw in the towel when the two meet for a grudge match in March.
The British duo will go head to head at the O2 Arena in an eagerly anticipated heavyweight bout, with neither man showing much love for the other in a feisty build-up.
At a media conference late last month, some pushing and shoving caused Haye to swing a punch at Bellew, who said afterwards he was shocked by his opponent's behaviour.
And Bellew, who retained his WBC cruiserweight title against BJ Flores in October, expects the 36-year-old Haye to give up if the going gets too tough.
"What I will tell you is, if this fight goes past four rounds, he's going to quit," he told Sky Sports.
"At some stage, it will get too hard and he will quit. He hasn't got the fight in him anymore.
"I love fighting. I am not 100 per cent in the head, I enjoy having a fight. We will see on March 4, where it happens, when it happens, but I must stress when I knock out David Haye on March 4 - I am then the best heavyweight in the world outside of them champions.
"Just let that sink in and think about where do I go from there."
Bellew recognises Haye as a fearsome customer, but is backing himself to prevail regardless of how long the contest ensues.
"He's possibly the most dangerous heavyweight in the world, including the champions. If I can drag him to the second half of the fight and to the deep waters, I will drown him, I will win easy, but I don't think it will get that far," Bellew said.
"I do believe this fight could be a four-round shootout and I am under no illusions if he catches me clean in the first four rounds I am going to have to get off the floor to win, but make no mistake he's going to have to do the same thing.
"The big difference between me and him, he hasn't got it in him to get off the floor."