22 Apr 1981
Kim Chul-Ho beats Jiro Watanabe via unanimous decision 15/15
Super Flyweight (115 lb)
8 Apr 1982
Jiro Watanabe beats Rafael Pedroza via unanimous decision 15/15
Jiro Watanabe becomes the WBA Super Flyweight world champion
29 Jul 1982
Jiro Watanabe beats Gustavo Ballas via corner retirement 9/15
11 Nov 1982
Jiro Watanabe beats Shoji Oguma via knockout 12/15
24 Feb 1983
Jiro Watanabe beats Luis Ibanez via knockout 8/15
23 Jun 1983
Jiro Watanabe beats Roberto Ramirez via majority decision 15/15
6 Oct 1983
Jiro Watanabe beats Kwon Soon-chun via technical decision 11/15
15 Mar 1984
Jiro Watanabe beats Celso Chavez via knockout 15/15
5 Jul 1984
Jiro Watanabe beats Payao Poontarat via split decision 12/12
Jiro Watanabe becomes the WBC Super Flyweight world champion
29 Nov 1984
Jiro Watanabe beats Payao Poontarat via knockout 11/12
9 May 1985
Jiro Watanabe beats Julio Soto Solano via unanimous decision 12/12
17 Sep 1985
Jiro Watanabe beats Kazuo Katsuma via knockout 7/12
13 Dec 1985
Jiro Watanabe beats Suk Hwan Yun via knockout 5/12
30 Mar 1986
Gilberto Roman beats Jiro Watanabe via unanimous decision 12/12