Naoya "Monster" Inoue easily retained his junior bantamweight world title in a third-round demolition of Yoan Boyeaux on Saturday at the Bunka Gym in Yokohama, Japan.
Inoue retained his 115-pound belt for the seventh time in a one-sided destruction as he knocked Boyeaux down four times overall to record a lopsided victory that probably will be his final title defense.
Inoue, who also won a world title at junior flyweight before moving up two divisions to win his current belt, would like to unify junior bantamweight titles. But since he has been unable to lure another titleholder into the ring with him, he plans to move up to bantamweight and pursue a title in that division.
So if the fight against Boyeaux was his swan song in the junior bantamweight division, he is leaving having put on a stellar performance.
Inoue (15-0, 13 KOs), 24, of Japan -- who is ranked No. 9 in the ESPN.com poll of best pound-for-pound fighters in the world -- scored the first knockdown when he crumpled Boyeaux (41-5, 26 KOs), 29, of France, with a clean left hand on the chin with about 15 seconds left in the first round.
Inoue continued to pressure Boyeaux throughout the bout. Boyeaux seemed more concerned with staying away from Inoue's punches than trying to land any of his own, but he couldn't stay away from Inoue for long.
Early in the third round, Inoue connected with a powerful left hook to the body, and Boyeaux took a step back and then went down to a knee for the second knockdown. Another left to the body dropped Boyeaux to a knee seconds later. Boyeaux was laboring but continued the fight, although he was backpedaling and looking to avoid any contact. But Inoue finally tracked him down and landed a few more punches, including yet another left to the body that dropped him the fourth time. Referee Raul Caiz Jr. did not bother to count and immediately waved off the fight at 1 minute, 40 seconds.
With Inoue planning to move up in weight, it likely means he will not appear on the all-junior bantamweight "Superfly 2" tripleheader on HBO on Feb. 24 at The Forum in Inglewood, California, as initially planned.
Inoue made his U.S. debut on the first "Superfly" card -- super flyweight is the alternate name for the junior bantamweight division -- on Sept. 9 and destroyed Antonio Nieves in the sixth round.
In the co-feature on Saturday, junior flyweight world titlist Ken Shiro (12-0, 6 KOs), 25, of Japan, retained his 108-pound belt for the second time in a fourth-round knockout of Gilberto Pedroza (18-4-2, 8 KOs), 25, of Panama.
Faster and more powerful, Shiro won all three rounds on all three judges' scorecards before dropping Pedroza with a flurry of punches in the fourth round. Moments later, Shiro dropped him again, and referee Laurence Cole waved the fight off at 1 minute, 12 seconds.
Also on the card, 2012 Japanese Olympic bronze medalist Satoshi Shimizu (5-0, 5 KOs), a 31-year-old southpaw who didn't turn pro until September 2016, knocked out the Philippines' Edward Mancito (15-8-2, 9 KOs), 25, to retain his regional featherweight belt. Shimizu knocked Mancito down four times en route to stopping him at 2 minutes, 8 seconds of the seventh round.
In another undercard fight, bantamweight prospect Takuma Inoue (10-0, 2 KOs), the 22-year-old brother of Naoya Inoue, won a unanimous decision against Japanese countryman Kentaro Masuda (27-9, 15 KOs), 34. The judges scored the fight 98-92, 97-93 and 96-94.