TOKYO: Japan’s unbeaten “Monster” Naoya Inoue defended his WBA and IBF bantamweight titles on Tuesday with an eighth-round technical knockout win over unheralded Thai challenger Aran Dipaen in Tokyo.

Fighting at Ryogoku Kokugikan — the home of sumo — Inoue wore Dipaen down with a series of punishing shots before dispatching him with a vicious left hand.

The bout, Inoue’s first in Japan for around two years, was widely seen as a stepping-stone toward an attempt at unifying all four bantamweight belts next year.

The 28-year-old took his unbeaten record to 22-0, with 19 wins by knockout.

Inoue unleashed his ferocious punching power to outclass Dipaen, the IBF’s sixth-ranked challenger.

Dipaen, who entered the fight with a 12-2 record, absorbed Inoue’s early blows but could do nothing when the champion hit him with a big left that sent him down to the canvas.

Inoue has set his sights on unifying the bantamweight belts next year, with WBA champion Nonito Donaire and WBO title-holder John Riel Casimero standing in his way.

Inoue beat Donaire in the final of the World Boxing Super Series in 2019, claiming a unanimous points win over the veteran Filipino after an epic contest.

But Donaire went on to win the WBC belt earlier this year, and defended it in style at the age of 39 against countryman Reymart Gaballo on Saturday.

Casimero, meanwhile, pulled out of his WBO title fight against Britain’s Paul Butler in Dubai on Saturday after missing the weigh-in.

Reports said the Filipino was admitted to hospital with viral gastritis, and the WBO has ordered him to present his medical documents before December 20 or face being stripped of his title.