Amir Khan posted the quickest victory of his pro career when he knocked out Vitali Martynov after 75 seconds to win his fifth lightweight contest on Saturday.

Rated the best boxing prospect in Britain since Lennox Lewis, Khan fired a straight right through the guard of the 22-year-old Belorussian, who had won 10 of his previous 11 fights, seven by knockout.

Although Martynov got to his feet, referee Terry O'Connor waved an end to the scheduled six-rounder as Khan, the Athens Olympic silver medallist, took another step toward what he hopes will be a world title.

``I can feel myself getting a lot stronger,'' Khan said. ``I trained very hard for it and I'm a bit upset it finished in the first round. I didn't even get hit in that fight.

``I would have liked to have shown a bit more of myself but it's the way the fight went.''