NONITO Donaire failed to slay 'The Monster' that is Naoya Inoue as the Japanese remained undefeated on Thursday after scoring a 12-round unanimous decision in their highly-charged title fight at the Saitama Super Arena.
Inoue had Donaire down in the 11th round of the potential Fight of the Year contender after connecting on a vicious left hook to the body that capped an outstanding performance in the final of the World Boxing Super Series bantamweight division.
Donaire lost via scores of 116-111, 114-113, and 117-109 but earned praise for a warrior attitude that saw him holding his ground against a fighter 10 years younger and clearly in his prime.
The 26-year-old Inouie retained his World Boxing Association (WBA) and International Boxing Federation (IBF) 118-lb title belts after improving to 19-0, with 16 KOs.
Donaire, 36, sufferred the seventh loss of his career in 47 fights (26 KOs), but gave the champion more than he can take after providing Inoue his toughest fight yet.
The Filipino opened a cut on Inoue's right eye following a thunderous left hook in the second round, but failed to capitalize on the moment and gave the Japanese the leeway to take control of the back and forth match.
Rocked by a couple of thunderous rights from the champion, Donaire rallied his way back and appeared to hurt Inoue in the ninth round when the challenger re-opened the cut on his right eye and had the Japanese's nose bleeding.
But Inoue found the perfect opening two rounds later when a left hook to the body had Donaire turning his back on him before going down on both knees grimacing in pain.
Donaire did finish the round - and the fight - on both feet, but the knockdown obviously clinched the win for the champion.
The Filipino, sporting welts on both eyes and in the forehead, was later taken to the hospital for precautionary measure but was also released later on.