6 Jun 1970
Ismael Laguna beats Guts Ishimatsu via knockout 13/15
Lightweight (135 lb)
8 Sep 1973
Roberto Duran beats Guts Ishimatsu via knockout 10/15
11 Apr 1974
Guts Ishimatsu beats Rodolfo Gonzalez via knockout 8/15
Guts Ishimatsu becomes the WBC Lightweight world champion
12 Sep 1974
Guts Ishimatsu and Arturo Pineda share a draw 15/15
28 Nov 1974
Guts Ishimatsu beats Rodolfo Gonzalez via knockout 12/15
27 Feb 1975
Guts Ishimatsu beats Ken Buchanan via unanimous decision 15/15
5 Jun 1975
Guts Ishimatsu beats Arturo Pineda via unanimous decision 15/15
4 Dec 1975
Guts Ishimatsu beats Alvaro Rojas via knockout 14/15
8 May 1976
Esteban de Jesus beats Guts Ishimatsu via unanimous decision 15/15
2 Apr 1977
Saensak Muangsurin beats Guts Ishimatsu via knockout 6/15
Super Lightweight (140 lb)