Unbeaten WBC, WBA, IBF bantamweight champion Naoya “Monster” Inoue (24-0, 21 KOs) added the WBO strap to his collection with the eleventh round knockout of Paul Butler (34-3, 15 KOs) on Tuesday night at Ariake Arena in Tokyo. Butler was in survival mode from the opener, opting to circle and backtrack away from the free swinging Inoue.

The Englishman looked to be on his way to the small victory of making it the distance but Inoue had other plans, finishing with a flutter in gaining the 21st knockout of his career in the eleventh. Time was 1:09.