Naoya Inoue delivered perhaps the most impressive win of his professional career by overcoming four-weight world champion Nonito Donaire on points in Japan.
Bantamweight Inoue won the World Boxing Super Series title and walked away with the IBF and WBA belts having been awarded the fight 116-111, 117-109 and 114-113.
Veteran Donaire, who fell to 40-6 with the defeat, took a knee after absorbing a brutal blow to the body early in the penultimate round but continued until the final bell.
Inoue, 26, sustained a deep cut above his left eye early in the fight and had to contend with blood pouring from the wound for the final four rounds.
"Donaire was a very, very strong opponent," Inoue, who improved to 19-0, said in the ring afterwards.
"This is my first cut in my career and I had double vision since the second round, but I was victorious. I am so happy. I believe I have a bright future.
"I think Donaire was a true champion, he's very strong and I was victorious but I'm not the greatest of all time yet.
"I think I have to get stronger. I will keep fighting, I want to be the strongest of all time."
Inoue started to take control of the bout in the fifth round when he rocked his opponent with a right, though he appeared in trouble in the eighth when a series of short left hooks from Donaire opened up a cut.
A counter right-hand from Donaire left Inoue wobbling, yet he recovered and soon started to deliver his combinations.
The end appeared nigh when a left to the body left Donaire distressed, and then down, as he eventually took a knee and just beat the 10 count.
Despite being barely able to move, he saw out that round - somehow delivering a big left of his own too - and was still standing when the bell rang at the end of the 12th, though Inoue was the clear victor when it went to the cards.