Japan's undisputed super bantamweight world champion Naoya Inoue opened the door for a fight in Las Vegas next year after retaining his titles against Ireland's TJ Doheny in Tokyo on Tuesday.

The undefeated "Monster" won by technical knockout in the seventh round at Ariake Arena when Doheny started hobbling and was unable to continue after injuring his hip.

The 31-year-old Inoue, who took his record to 28-0 with 25 wins by knockout, was making his second defense since becoming the undisputed super bantamweight world champion last December.