Openly conceding to having a huge chip on his shoulder, Brian Mendoza is promising to shatter Tim Tszyu's world-title dreams with a brutal display of sustained firepower.

Mendoza (22-2, 16KOs) is convinced Tszyu (23-0, 17KOs) won't be able to cope with his relentless counter-punching when Australian boxing's son of a gun puts his WBO super-welterweight belt on the line on the Gold Coast on Sunday.

The 29-year-old American is riding high after recording a thunderous against-the-odds knockout win over Sebastian Fundora to claim the WBC super-welterweight strap.

"Once he gets you — and he's a finisher and everything — but I think just based off the facts I have more explosive shots," Mendoza said after a workout in Sydney on Monday.

"The thing about me is I have power, but I'm not just a power puncher. I don't go in there trying to look for one shot. I'll hurt you for 12 rounds.

"I do look for the knockout. I do want to put on a big show. That's why I even got called here to this country in the first place for this title fight.

"But I'm in there to put punishment on you for 12 rounds — however long the fight needs to go for me to get that victory."

While he fully respects Tszyu, Mendoza says the bitter aftertaste of two defeats in 2019 and 2021 are fuelling his bid to end the Sydney slayer's undefeated career.

"I have a bigger chip on my shoulder. I have more to prove each time out," he said.

"I always hated to say that, but it is something I needed to go through, something I had to experience, because before you feel that taste of defeat, it's something impossible. It's unfathomable. You really don't think it's possible and then it kind of crushes in reality.