Spain's Kiko Martinez retained his International Boxing Federation super-bantamweight title on Wednesday by beating Japan's challenger ­Hozumi Hasegawa on a technical knockout in Osaka, Japan.

Referee Robert Byrd stopped the fight one minute and 20 seconds into the seventh round when Hasegawa was floored for the third time by the Spanish champion.

It was the 28-year-old's second defense of the title he won by knocking out Jonathan Romero of Colombia in August.