Australian boxing star Tim Tszyu is set for his biggest test to date as he challenges Tony Harrison for WBO super-welterweight interim world title.

The 28-year-old is undefeated in 21 fights but his matchup at Qudos Bank Arena will be the first he has fought for such a prize.

He was due to face Jermell Charlo for world titles in January, but a broken hand suffered by an American put a pause on those plans.

But this Sunday (March 12) it’s all set to go down with the Aussie challenging for the world title.

Speaking to reporters ahead of a mammoth weekend, Tszyu revealed how football superstar Cristiano Ronaldo had been helping him in his toughest training camp yet.

Credit: REUTERS / Alamy. He said, via Wide World of Sports: “Everything has been on point [in his preparation].

“I went and researched a little bit about Cristiano Ronaldo. I know he’s not a boxer but the way he approaches life is the way I am approaching life right now – as a true, 100 per cent athlete dedicated to his craft.

“Everything. Just the way I eat, when I eat, just true professionalism.

“I know when I was growing up my dad (Aussie boxing legend Kostya) was an army sergeant with the way he approached life and I’m times two to how he was.”

His opponent, Harrison, has a record of 29 wins and three losses, with 21 of those wins coming by way of knockout.

Similarly, the majority of Tszyu’s wins, 15 of 21 to be exact have also come by stoppage.

And despite the finish-ability of both men, Tszyu says he has been training to go the full distance and ensure he wins on judges’ decision should it come to that.

“The funny thing is that as the rounds go up and up and up, I feel like I don’t get tired,” he said.

“My breathing’s on point and everything’s just running smoothly.

“Right now I feel like I could run over anyone and it’s a good position and feeling to have, especially leading up to such a big fight.”

The Australian has certainly had his doubters, mainly coming from a crew of big name US fighters.

American superstar Errol Spence claimed he’d be putting $10,000 on a Harrison upset.

Tszyu labelled the undefeated boxer ‘a punk’ in response to the bet.