Nikita Tszyu survived his stiffest test to date, along with some unexpected drama along the way. 

The second-generation junior middleweight boxer overcame a controversial third-round knockdown to stop countryman Jack Brubaker in the sixth-round of their Main Event Pay-Per-View headliner. Brubaker showed world-class heart in the amount of punishment he withstood but too much for his corner who called for a stoppage midway through the sixth round Wednesday evening at Hordern Pavilion in Sydney, Australia. 

Instant comparisons were already sought from the moment the fight was announced, as Brubaker previously suffered a fourth round stoppage to Tim Tszyu, Nikita's older brother, in 2019. The younger Tszyu has sought to carve out his own name in the sport and is already fast-tracked in the infancy of his promising career. 

Both fighters let their hands fly in an entertaining opening round that saw Tszyu—the youngest fighting son of Hall of Fame legend Kostya Tszyu—have to deal with swelling around his right eye. The unbeaten 25-year-old twice rocked Brubaker late in round two but was also forced to withstand a right hand from the 'Cronulla Cowboy' in between those moments. 

Tszyu was issued an eight-count for the first time in his career in round three. A clash of heads forced Tszyu to the canvas but referee Brad Vocale ruled an official knockdown. He was unbothered by the sequence as he spent the rest of the fight inflicting pain and punishment on an all-too brave Brubaker. 

A stern warning was issued by the Brubaker (17-5-2, 8KOs) corner for the 31-year-old to find a way to turn things around and avoid their pulling the plug. Tszyu refused to allow a momentum shift, which ultimately forced the stoppage. 

Tszyu stormed to 7-0 (6KOs) as he picked up his deepest knockout win to date. He'd previously gone the full six-round distance in a virtual shutout of Ben Horn last July 20 at this very venue. His prior five stoppage victories all came in four or fewer rounds.

The evening's co-feature saw former title challenger Liam Wilson return to the win column with a ten-round, unanimous decision win over Argentina's previously unbeaten junior lightweight Carlos Maria Alanis (12-1, 4KOs).

Scores were 100-89, 100-89 and 98-91 for Wilson (12-2, 7KOs) in a relatively pedestrian affair. Wilson scored a knockdown in round seven, while Alanis played keep away for most of the rest of the bout. 

Wilson previously suffered a ninth-round knockout at the hands of Emanuel Navarrete in their February 3 WBO junior ligthweight title fight in Glendale, Arizona. The dramatic slugfest saw Navarrete suffer his first career knockdown late in round four but Wilson was unable to capitalize as he was later dropped and eventually stopped in their Fight of the Year contender.

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox