Conor McGregor claims he will finish off Eddie Alvarez in one round when UFC makes its debut in New York this weekend.
The Irish featherweight champion is bidding to make history against Alvarez by becoming the first man to hold two UFC titles at the same time.
McGregor, who knocked out Jose Aldo in 13 seconds to win the 145lb title in December, challenges Alvarez for his lightweight crown in the first UFC event staged in the Big Apple and the first in the state since a 19-year ban on the sport was lifted.
'Notorious', wearing a long mink coat, arrived fashionably late for Thursday's pre-fight press conference and played up to the 1,300-strong crowd by snatching the American's lightweight belt from where he had been sitting.
Alvarez, who had left the stage due to McGregor's absence, returned and retrieved his belt before the pair traded insults. The Dubliner then upped the stakes by raising a chair above his head and prepared to throw it at his rival.
UFC president Dana White intervened and once order was restored McGregor, who returns to the Octagon after gaining revenge over welterweight Nate in their rematch in August, predicted victory would cement his name in UFC history.
"This just puts it even more in stone," said McGregor. "A second belt, it's never been done. No one has ever come close, no one has attempted it. My legacy [is that] I'll be immortalised after this.
"I'm trying to live in the moment right now, this is such an historic event. I'll get the second world title.
"I believe that I will put this man away, but I am prepared for five rounds. I predict that I will rearrange his face. He's too easy to hit. I think [I'll beat him] in one round. If he can hold out and take it to the trenches, I'll take my hat off to him. But he will never be the same again."
Alvarez was embroiled in a number of verbal exchanges with McGregor before confidently stating: "I've always been the underground king in this sport."
He added: "I just have this belt and no one's getting it from me. I'm prepared to completely destroy Conor McGregor and silence this whole damn crowd."