The World Boxing Organisation (WBO) said, external it “mourns the passing of Japanese boxer Hiromasa Urakawa, who tragically succumbed to injuries sustained during his fight against Yoji Saito”.
It added: “This heartbreaking news comes just days after the passing of Shigetoshi Kotari, who died from injuries suffered in his fight on the same card.
“We extend our deepest condolences to the families, friends and the Japanese boxing community during this incredibly difficult time.”
Following the event, the Japan Boxing Commission announced all Oriental and Pacific Boxing Federation (OPBF) title bouts will now be 10 rounds instead of 12.
Urakawa is the third high-profile boxer to die in 2025 after Irishman John Cooney passed away in February following a fight in Belfast.
Cooney died aged 28 after suffering an intracranial haemorrhage from his fight against Welshman Nathan Howells.