South African-born Lovemore N'Dou scored a 12th-round TKO over Naoufel Ben Rabah in an IBF light welterweight eliminator in Sydney.
The victory could pave the way for a crack at Ricky Hatton as N'Dou became the new mandatory challenger to Britain's world champion.
However Hatton is likely to give up his belt and opt for a match-up with Mexico's Jose Luis Castillo.
N'Dou won Saturday's fight after Rabah voluntarily retired early in round 12.
N'Dou was ahead by one point on two cards and two points on the third at the time.
He lost to Britain's other light welterweight world champion Junior Witter in a Commonwealth title challenge in Los Angeles in February 2005.