British heavyweight Dereck Chisora stopped Hector Alfredo Avila after nine rounds in his first fight since losing to David Haye in July.
Chisora, 29, was fighting for the first time since his British licence was reissued in March , having been withdrawn after a brawl with Haye a year earlier.
He eventually stopped the Argentine to end a poor spectacle at Wembley Arena.
"It's done and now we move on to bigger and better things," said Chisora.
"The guy came to spoil and that made it difficult."
Argentinian Avila, who has now lost 13 of his 34 fights, has spent most of his career at cruiserweight but frustrated Chisora throughout a low-quality fight.
Chisora has targeted a fight with British heavyweight rival David Price later this summer.
Price's next fight is a rematch with Tony Thompson on 6 July.