Japan's Koki Kameda defeated Juan Landaeta of Venezuela by an unanimous decision on Wednesday to retain the WBA light flyweight title.
After a slow start, Kameda took control in the later rounds, knocking Landaeta to the canvas in the eighth round.
Kameda kept the challenger off balance for the remainder of the 12-round bout to keep the title he won in August. The judges scored the bout 119-108, 116-111 and 115-113 for Kameda.
Kameda improved to 13-0 with 10 knockouts while Landaeta slipped to 20-5 with 16 KOs.
Wednesday's fight was a rematch of a bout between the two boxers in August when Kameda won a contentious split decision against Landaeta to capture the title, reports AP.
Landaeta dominated the fight from the opening bell, knocking down the 19-year-old in the final seconds of the first round with a powerful right.
But the Japanese boxer walked away with the champion's belt after judges scored the bout 114-113 and 115-113 for Kameda against 115-112 for Landaeta.
Even Japanese fans at Yokohama Arena seemed shocked by the decision. By the 11th round, Kameda looked on the verge of collapse, delivering occasional head and body shots while his opponent sparred aggressively until the final bell.