Srisaket Sor Rungvisai scored a TKO victory in the eighth round over Yota Sato of Japan on Friday to win the WBC superflyweight title in his home town of Si Sa Ket.
Srisaket controlled the fight for most of the distance, but the resilient Sato refused to quit until the referee stepped in to prevent further damage.
It was Srisaket's 18th knockout in 20 bouts.
Sato, making the third defence of the title he won from Srisaket's Sor Rungvisai stablemate Suriyan 13 months ago, saw his record fall to 26-3-1.