Date: 2nd January 1973
Venue: Nihon University, japan
Title: WBA World Flyweight Title
( 34 - 2 - 1 )
Weight: 114 3/4 lbs
( 57 - 14 - 3 )
Weight: 109 1/4 lbs
Oba successfully defended his WBA world flyweight title at The Nihon University Auditorium with a 12th round knockout of Thailand's Chionoi.
Referee Yusaku Yoshida counted Chionoi out at 03:00 of the 12th round.