Here is a list of Yamaguchi's best fights. For a list of Yamaguchi's losses, refer to "Mamoru Yamaguchi Losses".
On October 4, 2014 Mamoru Yamaguchi faced off against Yosuke Saruta in a light-flyweight bout at age 37. He was coming in with a record of 27-9-4 (15), and Saruta was 27 years old and with a record of 9-4-2 (3). Yamaguchi stopped Yosuke Saruta via TKO.
On December 17, 2000 Mamoru Yamaguchi fought Jin Akimoto in a featherweight title fight for Akimoto's Shooto title. Yamaguchi was 23 years old and with a record of 6-0-1 (3), and Akimoto was 29 years old and with a record of 7-4-2 (3). Yamaguchi won the fight via 3-round unanimous decision and is crowned the new featherweight world champion.
On October 2, 2016 Mamoru Yamaguchi faced off against Luis Nogueira in a light-flyweight bout at age 39. He was coming in with a record of 30-10-5 (15), and Nogueira was 31 years old and with a record of 21-4-1 (11). Yamaguchi won the fight via 3-round split decision.
On December 7, 1999 Mamoru Yamaguchi faced off against Baret Yoshida at age 22. He was coming in with a record of 4-0 (2), and Yoshida was 24 years old and with a record of 1-0 (1). Yamaguchi stopped Baret Yoshida via TKO.
On September 5, 1999 Mamoru Yamaguchi faced off against Jin Akimoto at age 22. He was coming in with a record of 2-0 (0), and Akimoto was 28 years old and with a record of 5-3-2 (2). Yamaguchi won the fight via 2-round majority decision.
On December 17, 2005 Mamoru Yamaguchi faced off against Daiji Takahashi in a bantamweight bout at age 28. He was coming in with a record of 15-2-2 (7), and Takahashi was 28 years old and with a record of 6-7-2 (1). Yamaguchi won the fight via 3-round unanimous decision.
On August 27, 2000 Mamoru Yamaguchi faced off against Yoshinobu Ota at age 23. He was coming in with a record of 5-0-1 (3), and Ota was 27 years old and with a record of 3-1 (0). Yamaguchi stopped Yoshinobu Ota via KO.
On April 14, 2002 Mamoru Yamaguchi faced off against Hiroaki Yoshioka in a flyweight bout at age 24. He was coming in with a record of 8-1-1 (4), and Yoshioka was 28 years old and with a record of 4-3-2 (2). Yamaguchi won the fight via 3-round unanimous decision.
On May 3, 2004 Mamoru Yamaguchi faced off against Hiroaki Yoshioka in a bantamweight bout at age 26. He was coming in with a record of 11-2-1 (5), and Yoshioka was 30 years old and with a record of 5-6-2 (2). Yamaguchi stopped Hiroaki Yoshioka via KO.
On May 12, 2006 Mamoru Yamaguchi faced off against Setsu Iguchi in a bantamweight bout at age 28. He was coming in with a record of 16-2-3 (8). Yamaguchi stopped Setsu Iguchi via TKO.
