Nikita Tszyu has preserved the family name and his unbeaten record with a sixth-round stoppage of Jack Brubaker in their super-welterweight showdown in Sydney.

Making his much-hyped pay-per-view debut, Tszyu had promised violence and delivered, with the referee stopping the fight after Brubaker copped a pounding from the get-go on Wednesday night.

The TKO victory at the Horden Pavilion improved the 25-year-old's record to six knockout wins from his seven professional bouts.

Brubaker had been hoping to get one back on the Tszyu family after Nikita's now-world-champion brother Tim knocked him out in the fourth round four years ago.

The underdog was anything but disgraced, though, rocking Tszyu in the third round and staying on his feet throughout despite wearing a series of savage blows to the head.

"My first pay-per-view [fight] — this was the perfect test. Jack's a tough fighter," Tszyu said.

"I was hitting him with some pretty hard shots and he was talking back to me the whole time. It was a little annoying, to be honest. He's a real tough man.

"It was a great learning curve. I'm still learning every time I get into the ring. I'm only one and a half years into my career."

Tszyu landed three big punches to Brubaker's head in a lively opening round to assert his authority early in the Australian super-welterweight eliminator.

Brubaker endured more punishment in the second, one brutal right in particular stunning the 31-year-old.

But Brubaker refused to back down and the fight looked to have taken a nasty turn when the pair clashed heads in the third round.