Here is a list of Tanaka's best fights. For a list of Tanaka's losses, refer to "Kosei Tanaka Losses".
On March 16, 2019 Kosei Tanaka met Ryoichi Taguchi in a flyweight (WBO) world-title defense fight. Tanaka was 23 years old and with a record of 13-0 (7), and Taguchi was 32 years old and with a record of 27-3-2 (12). Tanaka won the fight via 12-round unanimous decision and successfully defended his title.
On May 20, 2017 Kosei Tanaka met Ángel Acosta in a light-flyweight (WBO) world-title defense fight. Tanaka was 21 years old and with a record of 9-0 (5), and Acosta was 26 years old and with a record of 16-0 (16). Tanaka won the fight via 12-round unanimous decision and successfully defended his title.
On December 31, 2015 Kosei Tanaka met Vic Saludar in a strawweight (WBO) world-title defense fight. Tanaka was 20 years old and with a record of 6-0 (3), and Saludar was 25 years old and with a record of 11-1 (9). Tanaka stopped Vic Saludar via 6th-round KO and successfully defended his title.
On August 24, 2019 Kosei Tanaka met Jonathan González in a flyweight (WBO) world-title defense fight. Tanaka was 24 years old and with a record of 14-0 (8), and González was 28 years old and with a record of 22-2-1 (13). Tanaka stopped Jonathan González via 7th-round TKO and successfully defended his title.
On March 31, 2018 Kosei Tanaka faced off against Ronnie Baldonado at age 22. He was coming in with a record of 11-0 (7), and Baldonado was 22 years old and with a record of 10-0-1 (7). Tanaka stopped Ronnie Baldonado via TKO.
On December 11, 2021 Kosei Tanaka faced off against Sho Ishida at age 26. He was coming in with a record of 16-1 (9), and Ishida was 30 years old and with a record of 29-2 (15). Tanaka won the fight via 10-round split decision.
On July 20, 2014 Kosei Tanaka faced off against Crison Omayao at age 19. He was coming in with a record of 3-0 (1), and Omayao was 21 years old and with a record of 17-7-2 (4). Tanaka stopped Crison Omayao via KO.
