5 Jun 1988
Hiroki Ioka and Napa Kiatwanchai share a draw 12/12
Minimumweight (105 lb)
13 Nov 1988
Napa Kiatwanchai beats Hiroki Ioka via majority decision 12/12
Napa Kiatwanchai becomes the WBC Minimumweight world champion
11 Feb 1989
Napa Kiatwanchai beats John Arief via unanimous decision 12/12
10 Jun 1989
Napa Kiatwanchai beats Hiroki Ioka via knockout 11/12
12 Nov 1989
Choi Jum-hwan beats Napa Kiatwanchai via knockout 12/12
8 Jun 1990
Hideyuki Ohashi beats Napa Kiatwanchai via unanimous decision 12/12
14 Sep 1992
Humberto Gonzalez beats Napa Kiatwanchai via knockout 2/12
Light Flyweight (108 lb)