On September 13, 2017, a 27-year-old Ryosuke Iwasa (23-2, 15 KOs) got a shot at the IBF super-bantamweight title held by Yukinori Oguni.
Iwasa came in to the fight on a 4-fight win streak with a 60% KO rate, and was fighting after a gap of 6 months and 11 days.
Ryosuke Iwasa stopped the champion via TKO in the 6th round of the 12-round world-title fight, winning the first world title of his career, and is crowned the new IBF super-bantamweight champion. Iwasa improves his record to 24-2 (16 KOs)
On December 7, 2019, a 29-year-old Ryosuke Iwasa (26-3, 16 KOs) and a 27-year-old Filipino boxer Marlon Tapales (33-2, 15 KOs) met in the ring in a super-bantamweight bout.
Iwasa came in to the fight on a 1-fight win streak with a 55% KO rate, and was fighting after a gap of 9 months and 21 days. Tapales was on a 12-fight win streak with a 42% KO rate, and fighting after a layoff of 6 months and 6 days.
Ryosuke Iwasa stopped Marlon Tapales via TKO in the 11th round. Iwasa improves his record to 27-3 (17 KOs), while Tapales adds a loss to his record at 33-3.
On March 1, 2018, the 28-year-old IBF super-bantamweight world champion, Ryosuke Iwasa (24-2, 16 KOs), faced Ernesto Saulong, in a title defense fight.
Iwasa came in to the fight on a 5-fight win streak with a 61% KO rate, and was fighting after a gap of 5 months and 16 days.
Ryosuke Iwasa defeated Ernesto Saulong via unanimous decision and successfully defended his IBF super-bantamweight title. Iwasa improves his record to 25-2
On October 25, 2021, a 31-year-old Ryosuke Iwasa (27-4, 17 KOs) and Genesis Servania met in the ring.
Iwasa came in to the fight on a 1-fight losing streak with a 54% KO rate, and was fighting after a gap of 6 months and 22 days.
Ryosuke Iwasa stopped Genesis Servania via KO in the 4th round. Iwasa improves his record to 28-4 (18 KOs)
On March 3, 2012, a 22-year-old Ryosuke Iwasa (10-1, 7 KOs) and Yuki Murai met in the ring in a bantamweight bout.
Iwasa came in to the fight on a 2-fight win streak with a 63% KO rate, and was fighting after a gap of 3 months and 14 days.
Ryosuke Iwasa stopped Yuki Murai via KO in the 1st round. Iwasa improves his record to 11-1 (8 KOs)
On December 6, 2013, a 23-year-old Ryosuke Iwasa (15-1, 9 KOs) and Hiroki Shiino met in the ring in a bantamweight bout.
Iwasa came in to the fight on a 7-fight win streak with a 56% KO rate, and was fighting after a gap of 5 months.
Ryosuke Iwasa stopped Hiroki Shiino via TKO in the 5th round. Iwasa improves his record to 16-1 (10 KOs)
On August 16, 2018, the 28-year-old IBF super-bantamweight world champion, Ryosuke Iwasa (25-2, 16 KOs), faced a 31-year-old Irish boxer TJ Doheny (19-0, 14 KOs), in a title defense fight.
Iwasa came in to the fight on a 6-fight win streak with a 59% KO rate, and was fighting after a gap of 5 months and 15 days. Doheny was on a 19-fight win streak with a 73% KO rate, and fighting after a layoff of 4 months and 30 days.
TJ Doheny defeated Ryosuke Iwasa via unanimous decision and wins the IBF title — in his first world-title fight. Doheny improves his record to 20-0, while Iwasa adds a loss to his record at 25-3.
On March 5, 2011, a 21-year-old Ryosuke Iwasa (8-0, 6 KOs) and a 28-year-old fellow Japanese boxer Shinsuke Yamanaka (13-0-2, 9 KOs) met in the ring in a bantamweight bout.
Iwasa came in to the fight on a 8-fight win streak with a 75% KO rate, and was fighting after a gap of 6 months. Yamanaka was on a 8-fight win streak with a 60% KO rate, and fighting after a layoff of 4 months and 9 days.
Shinsuke Yamanaka stopped Ryosuke Iwasa via TKO in the 10th round. Yamanaka improves his record to 14-0-2 (10 KOs), while Iwasa adds a loss to his record at 8-1.
On February 21, 2009, a 19-year-old Ryosuke Iwasa (2-0, 1 KO) and Ginzo Hanaki met in the ring.
Iwasa came in to the fight on a 2-fight win streak with a 50% KO rate, and was fighting after a gap of 4 months and 5 days.
Ryosuke Iwasa stopped Ginzo Hanaki via TKO in the 1st round. Iwasa improves his record to 3-0 (2 KOs)
On February 18, 2015, a 25-year-old Ryosuke Iwasa (18-1, 11 KOs) and Ricardo Roa met in the ring.
Iwasa came in to the fight on a 10-fight win streak with a 57% KO rate, and was fighting after a gap of 5 months and 12 days.
Ryosuke Iwasa stopped Ricardo Roa via TKO in the 2nd round. Iwasa improves his record to 19-1 (12 KOs)