Liborio Solis of Venezuela pounded out a points win over defending champion Kohei Kono of Japan to claim the World Boxing Association (WBA) super flyweight title on Monday.
Two of the judges had Solis ahead, 115-111 and 114-112, while the other scored it 113-113.
Kono counter-attacked with a straight right to knock Solis down in the second round. But the Venezuelan also had Kono on the canvas in the eighth after unleashing a left hook.
"I had to change my plan as I was downed in the second round, but I'm really happy that I won. I tried to knock him out, but he was too strong," said Solis.
The 31-year-old Venezuelan, the top-ranked challenger in the WBA, improved his record to 15 wins, including seven KOs, against three defeats and a draw.
For Kono, 32, it was his first defence of the title he took from Tepparith Kokietgym of Thailand in December. He saw his record reduced to 28 wins, including 11 KOs, against eight defeats.
Kono said: "I was very disappointed. His punches were stronger than I had expected. It affected me that I lost a penalty point by hitting a low blow in the 10th round."