Photo/Illutration Ryota Murata of Japan sends to right to Gennadiy Golovkin of Kazakhstan during their WBA/IBF middleweight unification boxing title match in Saitama, near Tokyo, Saturday, April 9, 2022. (AP Photo)

SAITAMA, Japan (AP) — Gennady Golovkin became the unified world middleweight champion with a ninth-round stoppage of Japanese fighter Ryota Murata on Saturday.

Kazakh boxer Golovkin, who turned 40 on Friday, sent his opponent to the canvas with a big right hand and Murata's corner threw in a towel.

Golovkin added Murata's WBA title to his IBF and IBO belts after his first fight since December 2020.

A third bout against Canelo Alvarez could be next for Golovkin, whose only defeat in his 44-fight professional career came at the hands of the Mexican boxer.

Golovkin was shaken in the early rounds but a right hook, which saw Murata's mouthguard fly across the ring, in the fifth changed the course of the fight.