Tim Tszyu battered Takeshi Inoue in a one-sided demonstration that he is ready for the world title scene on Wednesday in Australia.
Tszyu knocked Inoue down for the only time in the 12th round but was forced to settle for a comfortable unanimous decision victory.
The Australian, whose father Kostya Tszyu was a pound-for-pound great who fought Ricky Hatton, is the mandatory challenger to WBO super-welterweight champion Brian Castano.
Tszyu's shot at a world title could come soon after he extended his unbeaten record to 20-0.
Tszyu pulverised Inoue to the body but his run of five consecutive stoppages was brought to a halt simply by his opponent's toughness.
Inoue partly lost his footing in the final round when he finally touched the canvas.
"The guy's built like a brick wall," Tszyu said. "I don't think any heavyweights can drop him. I'm sure he's going to be sore tomorrow.
"I heard him squeal, his face is battered and look at his body. He's so tough."
Sky Sports Boxing schedule
November 20 - BOXXER in London
Richard Riakporhe vs Olanrewaju Durodola
Florian Marku vs Jorick Luisetto
Hosea Burton vs Dan Azeez - British light-heavyweight title
Mikael Lawal
November 20 - Top Rank in Las Vegas
Terence Crawford vs Shawn Porter - WBO welterweight title
December 11 - BOXXER in Cardiff
Chris Eubank Jr vs Liam Williams
Claressa Shields vs Ema Kozin
December 11 - Top Rank in New York
Vasiliy Lomachenko vs Richard Commey
Jared Anderson vs Oleksandr Teslenko
Nico Ali Walsh
Xander Zayas
December 17 - Top Rank in Montreal
Artur Beterbiev vs Marcus Browne - IBF and WBC light-heavyweight titles
February 26 - Top Rank in Glasgow
Josh Taylor vs Jack Catterall - undisputed super-lightweight title