On Tuesday in Tokyo, Japanese superstar Naoya Inoue, 28-year-old, retained his WBA and IBF bantamweight titles with an eighth-round stoppage over huge underdog and mandatory challenger Aran Dipaen of Thailand.

Inoue broke down Dipaen round after round before closing the show in the eight with a series of heavy power shots.

For Inoue, it was his first contest in Japan in two years.

Inoue (22-0, 19 KOs) had to work harder than expected and was shocked at Dipaen's ability to take his shots.

"He used to be a Muay Thai fighter and he brought that toughness," Inoue said. "I started to wonder whether my punches were having an effect -- that's how tough he was."

"The fight didn't go as everyone was expecting, but it was good to fight in Japan again after two years."

Inoue would now like to unify more titles in his weight class - and he hopes to secure fights with WBC champion Nonito Donaire and WBO beltholder John Riel Casimero.

Last Saturday, Donaire knocked out Reymart Gaballo and expressed his interest in facing Inoue in a unification rematch.

In a Fight of The Year battle, Inoue won a tough twelve round decision over Donaire in 2019, in the final round of the World Boxing Super Series bantamweight tournament.

Casimero was set to face mandatory challenger Paul Butler last Saturday in Dubai, but he was forced to withdraw due to medical reasons. Their fight was postponed to next year. There is a possibility Casimero will be stripped - as the sanctioning body wants medical records to substantiate his illness.

If no unification is secured, then Inoue will move up to super bantamweight.

"I've been placing a lot of importance on unifying the four belts, but if the individual fights don't happen, I'll start thinking about the super bantamweight title," Inoue said.