Stadium: Centre Court Round: 25 Ground: Hardcourt outdoor
| Nonthaburi, Singles M-ITF-THA-01A | 2020/01/26 07:50 | Issei Okamura v Kovapitukted, Palaphoom | 4-6,1-6 |
| Hong Kong, Simples M-ITF-HKG-01A | 2020/01/08 06:50 | El Midhawy, Adam v Issei Okamura | 4-6,6-2,6-3 |
| Hong Kong, Simples M-ITF-HKG-01A | 2020/01/07 02:00 | Issei Okamura v Kaewsuto, Chayanon | 6-0,6-0 |
| Hong Kong, Simples M-ITF-HKG-01A | 2020/01/06 02:00 | Issei Okamura v Geiwald, Douglas | 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 | Kim, Cheong-Eui v Issei Okamura | 6-4,4-6,6-4 |
| Toowoomba, Simples M-ITF-AUS-08A | 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 Ghinda, Iancu-Lustinian | 6-2,6-3 |
| ITF - M15 Sharm El Sheikh | 2020/02/17 09:00 | Piotr Grynkowski v Onishi, Ken | 6-1,6-4 |
| ITF - M15 Sharm El Sheikh | 2020/02/12 08:00 | Vivero Gonzalez, Pablo v Piotr Grynkowski | 6-3,6-3 |
| ITF - M15 Sharm El Sheikh | 2020/02/11 08:00 | Uzhylovsky, Vladimir v Piotr Grynkowski | 6-4,6-4 |
| ITF - M15 Sharm El Sheikh | 2020/02/10 09:00 | Ernaelsteen, Victor v Piotr Grynkowski | 2-6,2-6 |
| ITF - M15 Sharm El Sheikh | 2020/02/09 10:00 | Hiramatsu, Shinnosuke v Piotr Grynkowski | 3-6,0-6 |
| Milovice, Singles M-ITF-CZE-10A | 2019/11/14 13:45 | Piotr Grynkowski v Vadym Ursu | 2-6,1-6 |
| Milovice, Singles M-ITF-CZE-10A | 2019/11/13 09:00 | Piotr Grynkowski v Samuel Puskar | 6-3,6-0 |