It appears likely that Naoya Inoue is heading in the direction of an undisputed fight in the fall.

On Tuesday night in Tokyo, Inoue moved up to the super bantamweight division and picked up an eight round knockout over unbeaten Stephen Fulton to capture the WBO, WBC world titles.

The victory made Inoue a four division world champion. He's the second boxer in Japanese history to reach that accomplishment. The first was Kazuto Ioka, who currently holds the WBA world title at super flyweight.

Last December, Inoue became the undisputed world champion at bantamweight with a knockout of Paul Butler. Inoue is the first Japanese boxer to become undisputed in the four belt era.

Against Fulton, Inoue was facing his biggest opponent to date. After controlling the bulk of the fight, Inoue dropped Fulton hard in the eight. Fulton made it up, but then saw himself battered with shots until the referee stepped in as he was going down for a second time.

After the fight was over, WBA/IBF super bantamweight champion Marlon Tapales of the Philippines entered the ring and called for a fight with Inoue. Tapales, who was sitting ringside, had planned for some time to challenge the Inoue-Fulton winner to an undisputed showdown.

"I want to fight Naoya Inoue. I want to prove to myself that I'm a champion," Tapales said.

Inoue wants the fight with Tapales to take place later this year.

Tapales (37-3, 19 KOs) pulled off a big upset earlier this year, when he unseated unbeaten Murodjon Akhmadaliev to capture the IBF, WBA world titles with a twelve round split decision win in San Antonio, Texas.

Tapales has now won four fights in a row since suffering a knockout loss to another Japanese fighter, Ryosuke Iwasa, back in 2019. Iwasa was then knocked out in five by Akhmadaliev.