Former footballer Leon McKenzie won his first fight as a boxer when he beat John Mason in their super-middleweight contest at York Hall in London.
McKenzie, who played in the Premier League as a striker for Norwich, overwhelmed 29-year-old Mason, who had lost his last five fights.
The 35-year-old twice sent Mason to the canvas before the bout was stopped.
McKenzie, son of former British and European champion Clinton, could fight again in September.
He is trained by uncle and former three-time world champion Duke and switched to boxing after retiring from football in December 2011.
McKenzie scored 115 goals in 405 games for eight clubs. He since had depression and was jailed for trying to avoid speeding convictions before embarking on his boxing career.