Liborio Solis, stripped of his WBA super-flyweight champion belt for being overweight, has beaten IBF holder Daiki Kameda on a split decision in what would have been a unification title bout in Osaka.
Venezuelan Solis failed to make the 52.1kg limit in Monday's weigh-in and lost his World Boxing Association title in the division.
The 24-year-old Kameda retained his International Boxing Federation crown, officials said after the bout.
There was no knockdown in the 12-round bout at the Osaka Bodymaker Colosseum, with the two boxers exchanging blows in close range.
Three US judges gave a 2-1 decision with Joe Garcia and Valerie Dorsett scoring 116-112 in favour of Solis. Robert Hoyle carded Kameda the winner by 115-113.
"It makes me feel happy to win but unfortunately I could not unify the title," Solis told reporters through an interpreter.
"I feel responsible for my failure to make the weight."
The weigh-in on Monday bordered on the farcical.
In his first weigh-in, Solis was 1.4 kg above the 52.1 kg limit.
He was still 1.1 kg overweight in his second weigh-in an hour later and refused to step on the scales for a third time inside the two-hour time limit to make the weight.
As soon as he gave up his attempt, Solis was seen gulping down water from a plastic bottle and buying cans and bottles of soft drinks from a vending machine, Japanese media said.
"I won't reduce my weight any more. I cannot make it because it is too cold in Japan," he was quoted as saying.
"I ran for one hour but it didn't help. I cannot sweat any more if I move around for another hour."
The WBA is expected to fine him for his failure and he will have to return his fight money to promoters.
