Kazuto Ioka will defend his WBA flyweight crown on Sept. 27, his gym said Thursday.

Ioka, who has won world titles in three weight classes, will take on Argentina's Roberto Domingo Sosa at Osaka Prefectural Gymnasium.

"I want to prove myself as the strongest flyweight," Ioka told a news conference in Osaka. "The most important thing is to perform well.

"He (Sosa) has a long reach and a lot of extension on his straight punches."

Ioka's career record is 17-1 with 10 knockouts, while Sosa is 26-2 with one draw and 14 knockouts.