The victory saw the Japanese star retain his WBC bantamweight title for the first time, with official scores of 120-106, 119-107 and 118-108.

Inoue (22-2, 5 KOs) turned in a career-best performance in his biggest fight to date, dropping legendary four-weight world champion Ioka in the second and third rounds with eye-catching power shots in a sizzling display.

With an early statement made, Inoue, more boxer than brawler, then activated cruise control.

"It was fun, really," said Inoue during his post-fight interview. "Thank you to Ioka for fighting me.

"If possible, I would like to fight in a title unification. That's something I've wanted for a long time."

In the opening round, it was Inoue's speed and precision against Ioka's timing and power punching. The ex-champ scored a pair of meaningful rights, but was outworked by Inoue, who settled into a nice rhythm. The pattern was set.

The jab was the signature shot for the defending titleholder early and it snapped Ioka's head back with ominous regularity. Still, it came as a shock when a perfect counter right and a sharp follow-up attack decked the former champion in the second.

The field day continued when a flush right uppercut had Ioka over again in the opening minute of round 3. A quick finish looked likely, but the super durable Ioka still had his legs and stubbornly stayed in pursuit.

Showing plenty of heart, Ioka scored his most meaningful punch – a powerful left hook – in the fourth, which was a session he could have won on work rate. It was a long way back, however, and he was down 40-36, 39-35, 39-35 on open scoring through four.

The action drifted to the inside for the first time in the sixth, and again Inoue was superior. He caught Ioka repeatedly on the counter with power shots and his hand speed was decisive in every exchange.

Inoue was also excellent defensively. Ioka would open up with combinations near the ropes but was continually made to flounder by the rapid-fire champion, who moved his head and pivoted around the older man effortlessly.

It was a near-masterclass from Inoue, reflected in the official scoring after eight rounds: 80-70, 79-71, 79-71.

The final third of the bout was largely uneventful, though Ioka did manage to score another hard left hook in the 11th. Inoue acknowledged it with a smile, but there was no serious damage.

Inoue won the 12th, rocking Ioka in the closing moments.

Following in the footsteps of an iconic fighter like Naoya Inoue can't have been easy, but Takuma has embraced the challenge, made the sacrifices, and produced the results when it mattered most.

To beat Tenshin Nakukawa and Ioka in back-to-back fights is impressive and sets the Japanese fighter up for a revenge mission against WBA titleholder Seiya Tsutsumi, who outpointed Inoue in October 2024, or possibly an alternate unification match against Mexico's WBO belt holder Christian Medina.

"I am not just the brother of Naoya," said the champion. "That was me, Takuma Inoue."

Ioka (32-5-1) has been a wonderful ambassador for boxing and has accomplished so much. Now would be a good time for him to sail off into the sunset. He was made to look very old tonight by a younger and superior fighter.

Former world title challenger Jin Sasaki went through a torrid time in winning a 10-round split decision over Soro Tanaka at welterweight. The official scores were 97-93, 96-94 and 94-96.

Tanaka, a former amateur standout, touched gloves with Sasaki upon entering the ring, then touched his chin with a crazy assortment of combination punching in the early rounds. Flush uppercuts caught the habitually leaky Japanese fighter flush, with some of the action uncomfortable to watch.

Open scoring at the end of five rounds had Sasaki ahead, which came as a surprise to members of press row. Tanaka's accuracy and work rate had definitely dipped, but he was still landing withering shots to head and body.

Sasaki (21-2-1, 18 KOs) came to life in the middle rounds and made a real target of the body.

However, the defensive lapses that saw him at the wrong end of The Ring's Knockout of the Year against Brian Norman last year still remain. Tanaka loses for the first time and is now 5-1.

Yuito Moriwaki retained a couple of domestic super middleweight title belts with a hard-fought, albeit messy, 10-round split decision win over Deok No Yun (10-3-1, 8 KOs). Both fighters stood in the pocket and traded in every round, but neither man was visibly shaken.

Two judges preferred the work of Moriwaki, submitting scores of 96-94 in his favor, while the third official went with Yun at 97-93. Moriwaki improves to 2-0-1, while Yun is now winless in his last two appearances and falls to 10-3-1.

In high-contact flyweight action, Kosuke Tomioka and Shogo Tanaka battled to a 10-round split draw.

Official scores were 97-93, 96-94 and 95-95. Tomioka (11-4-1, 8 KOs) sustained a nasty cut over his left eye in the middle rounds but did enough to retain a regional WBO belt at 112 pounds while Tanaka (5-0-1, 3 KOs) will go back to the drawing board after a hard-fought result with his unbeaten record still intact.

During an all-southpaw matchup, Toshiki Shimomachi (23-1-3, 12 KOs) outpointed countryman Reiya Abe (28-5-2, 10 KOs) via 10-round majority decision at featherweight.

Neither fighter was hurt in a nip-and-tuck affair that could have gone either way. Shimomachi continues a decade-long unbeaten streak after banking his first appearance of the year, while former IBF title challenger Abe suffers his fifth career defeat.