Takuma Inoue of Japan beat Liborio Solis of Venezuela to win the empty WBA bantamweight title.
In the fifth round, a stray elbow hit Inoue above the eye, leaving him with a deep cut. But he still won by unanimous decision in Tokyo.
The 27-year-old used to hold the WBC interim bantamweight title from 2018 to 2019. His record now stands at 18-1, with four knockouts.
This year, the belt was given to his younger brother, Naoya.
“This is the belt that my brother used to have, and it was the first one he won, so I’m glad to get it,” said Inoue, whose brother was watching from the stands.
“My brother had all four belts, and I want to say that it is now my challenge to do the same. I want to be the undisputed champion.”
When he beat England’s Paul Butler in December, Naoya Inoue became the first undisputed bantamweight world champion since Panama’s Enrique Pinder in 1972.
The 29-year-old fighter, who has a record of 24-0 with 21 knockouts, gave up all four belts the next month to move up to the super-bantamweight division.
In Tokyo in July, he will fight WBC and WBO champion Stephen Fulton of the United States.