Here is a list of Oishi's best fights. For a list of Oishi's losses, refer to "Masahiro Oishi Losses".
On November 25, 2001 Masahiro Oishi fought Mamoru Yamaguchi in a featherweight title fight for Yamaguchi's Shooto World title. Oishi was 32 years old and with a record of 8-5-3 (5), and Yamaguchi was 24 years old and with a record of 7-0-1 (4). Oishi stopped Mamoru Yamaguchi via 1st-round submission and is crowned the new featherweight world champion.
On July 30, 2005 Masahiro Oishi faced off against Jin Akimoto in a featherweight bout at age 36. He was coming in with a record of 12-9-6 (7), and Akimoto was 34 years old and with a record of 11-8-2 (5). Oishi stopped Jin Akimoto via choke-out.
On March 2, 2001 Masahiro Oishi faced off against Yoshinobu Ota at age 32. He was coming in with a record of 7-5-3 (4), and Ota was 28 years old and with a record of 3-2 (0). Oishi stopped Yoshinobu Ota via submission.
On October 4, 1996 Masahiro Oishi faced off against Katsuhisa Akasaki at age 27. He was coming in with a record of 2-1-2 (1), and Akasaki was 22 years old and with a record of 0-1 (0). Oishi stopped Katsuhisa Akasaki via submission.
On March 1, 1998 Masahiro Oishi faced off against Yoshihiro Fujita at age 29. He was coming in with a record of 4-2-2 (1), and Fujita was 28 years old and with a record of 0-1 (0). Oishi stopped Yoshihiro Fujita via choke-out.
On February 27, 2016 Masahiro Oishi faced off against Hirotaka Miyakawa in a bantamweight bout at age 47. He was coming in with a record of 25-18-9 (19). Oishi stopped Hirotaka Miyakawa via submission.
On November 10, 2007 Masahiro Oishi faced off against Artemij Sitenkov in a featherweight bout at age 38. He was coming in with a record of 17-10-7 (12). Oishi stopped Artemij Sitenkov via submission.
On November 3, 2010 Masahiro Oishi faced off against Hirokazu Nishimura in a bantamweight bout at age 41. He was coming in with a record of 21-14-7 (15). Oishi stopped Hirokazu Nishimura via TKO.
On August 8, 2010 Masahiro Oishi faced off against Takumi Murata in a bantamweight bout at age 41. He was coming in with a record of 20-14-7 (14). Oishi stopped Takumi Murata via submission.
On April 23, 2006 Masahiro Oishi faced off against Sergej Juskevic in a featherweight bout at age 37. He was coming in with a record of 14-9-6 (9). Oishi stopped Sergej Juskevic via submission.