Takuya Kogawa lost a close decision to Thai Yodmongkol Vorsaengthep on Tuesday in a bid for the interim WBA flyweight crown.
The judges gave the 2-0 decision to Yodmongkol in the 12-rounder in Nakhon Ratchasima, Thailand.
"I was the weaker fighter," said the 28-year-old Kogawa. "I felt the pressure of fighting on the round. I felt that I wasn't able to win a decision in Thailand. I'm not thinking of retiring even though I lost," he said.