Stadium: Centre Court Round: 25 Ground: Hardcourt outdoor
| ITF - M25 Nonthaburi | 2020/01/26 07:50 | Issei Okamura v Palaphoom Kovapitukted | 4-6,1-6 |
| ITF - M15 Hong Kong | 2020/01/08 06:50 | Adam El Mihdawy v Issei Okamura | 4-6,6-2,6-3 |
| ITF - M15 Hong Kong | 2020/01/07 02:00 | Issei Okamura v Chayanon Kaewsuto | 6-0,6-0 |
| ITF - M15 Hong Kong | 2020/01/06 02:00 | Issei Okamura v Douglas Geiwald | 6-2,6-1 |
| ITF - M15 Cancun | 2019/11/15 19:35 | Issei Okamura v Mariano Kestelboim | 4-6,1-6 |
| ITF - M15 Cancun | 2019/11/05 16:35 | Mateus Alves v Issei Okamura | 6-3,6-2 |
| ITF - M15 Changwon | 2019/10/15 03:10 | Cheong-Eui Kim v Issei Okamura | 6-4,4-6,6-4 |
| ITF M25 Toowoomba | 2019/10/08 01:50 | Issei Okamura v Tristan Schoolkate | 3-6,6-2,4-6 |
| ITF - M15 Sharm El Sheikh | 2020/02/18 09:30 | Piotr Grynkowski v Iancu-Iustinian Ghinda | 6-2,6-3 |
| ITF - M15 Sharm El Sheikh | 2020/02/17 09:00 | Piotr Grynkowski v Ken Onishi | 6-1,6-4 |
| ITF - M15 Sharm El Sheikh | 2020/02/12 08:00 | Pablo Vivero Gonzalez v Piotr Grynkowski | 6-3,6-3 |
| ITF - M15 Sharm El Sheikh | 2020/02/11 08:00 | Volodymyr Uzhylovskyi v Piotr Grynkowski | 6-4,6-4 |
| ITF - M15 Sharm El Sheikh | 2020/02/10 09:00 | Victor Ernaelsteen v Piotr Grynkowski | 2-6,2-6 |
| ITF - M15 Sharm El Sheikh | 2020/02/09 10:00 | Shinnosuke Hiramatsu v Piotr Grynkowski | 3-6,0-6 |
| ITF - M15 Milovice | 2019/11/14 13:45 | Piotr Grynkowski v Vadym Ursu | 2-6,1-6 |
| ITF - M15 Milovice | 2019/11/13 09:00 | Piotr Grynkowski v Samuel Puskar | 6-3,6-0 |