| UTR Pro Tennis Series Florida | 2021/09/14 13:30 | Sysoev, Nikolay v Schmid, Michal | 6-7,2-5 |
| UTR Pro Tennis Series Florida | 2021/09/13 12:00 | Sysoev, Nikolay v Omar Maldonado | 7-6,6-4 |
| ITF - M15 Monastir | 2021/08/01 09:00 | Baird, Drew v Sysoev, Nikolay | 6-1,6-2 |
| ITF - M15 Monastir | 2021/07/25 08:00 | Sysoev, Nikolay v Ansari, Austin Ansari | 2-6,0-6 |
| ITF - M15 Monastir | 2021/07/19 09:00 | Sysoev, Nikolay v Joshua Sheehy | 2-6,1-6 |
| ITF - M15 Monastir | 2021/07/18 09:00 | Calvo Barcelo, Fermin v Sysoev, Nikolay | 3-6,6-4,6-10 |
| ITF - M15 Monastir | 2021/07/11 09:00 | Evgeny Philippov v Sysoev, Nikolay | 6-2,6-1 |
| ITF - M15 Monastir | 2021/07/05 09:00 | Lorenzo Rottoli v Sysoev, Nikolay | 6-1,6-4 |
| UTR Pro Tennis Series Florida | 2021/09/14 16:30 | Omar Maldonado v Postolka, Roman | 0-6,3-5 |
| UTR Pro Tennis Series Florida | 2021/09/12 12:00 | Rowland Phillips v Postolka, Roman | 7-6,6-1 |
| UTR Pro Tennis Series Florida | 2021/09/11 16:30 | Postolka, Roman v Michal Lusovsky | 6-2,7-5 |
| UTR Pro Tennis Series Florida | 2021/09/10 18:30 | Jacob Perkins v Postolka, Roman | 3-6,1-6 |
| UTR Pro Tennis Series Florida | 2021/09/09 14:30 | Kiranpal Pannu v Postolka, Roman | 6-1,6-3 |
| UTR Pro Tennis Series Florida | 2021/09/07 15:00 | Parth Aggarwal v Postolka, Roman | 1-6,1-6 |
| UTR Pro Tennis Series Florida | 2021/09/06 18:30 | Postolka, Roman v Dusty Boyer | 6-4,4-6,6-6 |
| Prostejov, Singles M-ITF-CZE-04A | 2021/08/15 10:00 | Dominique Graf v Postolka, Roman | 6-3,5-7,10-7 |