The pair have engaged in a bitter war of words over the past few months but will draw a line under all the chit-chat on Saturday night at the T-Mobile Arena here in Las Vegas.

The stakes could not be higher for the pair, who know that victory is likely to set up a world title shot against the winner of the evening’s main event between Saul ‘Canelo’ Alvarez and WBA and WBC middleweight champion Gennady Golokin.

Dislike between fighters, particularly during the whirlwind of a Sin City fight week, is nothing new but much of the verbal jousting between the Mahon man and his French-Canadian opponent has been more than crass.

O’Sullivan has spoken of sending 29-year-old Lemieux into retirement, while the Montreal resident even made reference to his opponent’s 2009 conviction for assaulting his former partner.

But Lemieux stepped it up yet another gear by claiming that he is hoping to not simply win on Saturday night, but to maim O’Sullivan in the process.

The former IBF champion said: “It’s definitely not going the distance, I won’t let that happen, but I want to torture him a bit before.

“He’s a tough guy so he might make it to five rounds but we’ll see.

“I want to damage him, for life. I want to cut his head off. He is very disrespectful guy, he has no class.

“But I’m staying focused, it’s all just putting fuel on the fire.

I’m just going to be a lot more dangerous in the fight. I’m going to give him a lot less mercy. He is a very trashy type of guy, he talks all types of things on social media.

Indeed, the dislike appears to stem from an ongoing Twitter spat between the pair but the animosity was not always thus.

They crossed paths in Montreal in December when Lemieux fought Englishman Billy Joe Saunders, for the world title on a show in which 34-year-old O’Sullivan featured.

In fact, Lemieux, who has 33 wins and four defeats on his record, claims his rival this time around actually asked him for a photograph and the pair smiled alongside each other like friends.

“He asked me for a picture,” Lemieux said. “I didn’t know him back then. I said ‘yeah sure’, just like I would say to any other fan I would give a picture to.

He didn’t open his mouth so I didn’t know him, now he opens his mouth I can hear what kind of trash he is. I’ll take care of him on Saturday.

“I know when I start landing my shots I will be breaking some bones in there. I’m going to break all his bones.

“Viewers’ discretion is advised. Whoever is sensitive, please be careful. If there are kids around, don’t let them watch.

“It’s going to be brutal.”