Nelson Asofa-Solomona has knocked out his fellow ex-NRL star Jarrod Wallace in three brutal rounds on the undercard of Tim Tszyu's fight in Wollongong on Sunday.

The former Melbourne Storm enforcer knocked Wallace down by pinning him on the ropes and hitting him with a sledgehammer right hand, then connecting with an uppercut and more rights to the head.

Wallace had shocked the crowd by taking it to Asofa-Solomona in the first two rounds of the fight, momentarily wobbling the 135kg giant before both men crashed to the canvas as they tackled each other, rugby league-style.

It's the second time Asofa-Solomona has knocked Wallace out in the ring, with the pair first clashing in an exhibition bout in late 2023.

The ex-prop was cut during the fight and was warned for holding in the first round.

Asofa-Solomona then turned his attention to former Souths front-rower George Burgess, who was sitting ringside for the bout and joined him in centre ring after the result.

The Englishman said he and promoter No Limit have signed a contract that will see him fight Asofa-Solomona, and explained that he has previously done boxing training with Aussie legends Jeff Fenech and Danny Green.

Asofa-Solomona told the crowd he has 'a lot of respect' for Wallace, admitted he has 'a lot of learning to do', then singled out Burgess.

'I know there's a big boy here, big Georgie pie wants it,' he said.

'I would love some English breakfast.

'Yesterday on a video you looked like a stiff board [while boxing].

'If you want to come and see me, let's make it work.'

When Burgess pointed out the cut 'Big Nasty' suffered in the fight and promised to give him the same treatment, the sledging went up a notch.

'You wouldn't know what this is, bro. This is hard work,' Asofa-Solomona said.

'Your breath smells like beer, get out of my face.'

In other bouts on the Tszyu undercard, local talent Sam Goodman scored a unanimous points victory over Argentina's Rodrigo Ruiz in a hard-fought 12-round super bantamweight clash.

Callum Peters blasted out Delio Anzaqeci Mouzinho in a two-round knockout victory, Aussies Charlie Kazzie and Blair Geraghty earned an entertaining majority draw and Paulo Aokuso smashed Kittipong Jian Hao Ho in a lopsided one-rounder, with the Thai fighter struggling badly with a knee injury.