Ginjiro Shigeoka and his older brother Yudai both won minimumweight world championships Saturday, with the 23-year-old Ginjiro seizing the IBF championship by technical knockout and his 26-year-old brother winning the WBC belt by decision.
Ginjiro, who took to the ring ahead of his older brother, knocked down Mexico's Daniel Valladares before stopping him in the fifth round of their long-awaited rematch at Ota City General Gymnasium. He remains undefeated at 10-0 as a pro with eight knockouts.
"My older brother and I worked hard to become official champions," said Ginjiro, who like his brother started the day as an interim champion.
Ginjiro Shigeoka's first title fight against Valladares in January was declared a "no-contest" after he inadvertently head-butted the Mexican. An August rematch was rescheduled after Shigeoka suffered a foot injury.
Valladares' record fell to 27-4-1 with the one no-contest.
Yudai Shigeoka also remained undefeated, improving to 8-0 in his career following his win over Thailand's Panya Pradabsri, whose record now stands at 40-2 with 24 knockouts.
"I wanted to praise my effort whether I won by knockout or decision," Yudai said. "I could hear everyone's cheers and it made me stronger."