| ITF M15 Telavi | 2021/08/04 08:45 | Evgeny Philippov v Gabriel Donev | 2-6,3-6 |
| ITF M15 Telavi | 2021/08/03 09:45 | Martin Borisiouk v Gabriel Donev | 3-6,2-6 |
| ITF M15 Novi Sad | 2021/07/30 08:00 | Gabriel Donev v Juan Pablo Paz | 4-6,5-7 |
| ITF M15 Novi Sad | 2021/07/29 09:25 | Gabriel Donev v Gorazd Srbljak | 6-2,6-4 |
| ITF M15 Novi Sad | 2021/07/28 11:10 | Ivan Nedelko v Gabriel Donev | 4-6,1-6 |
| ITF M15 Novi Sad | 2021/07/26 09:00 | Gabriel Donev v Dusan Rajic | 6-2,6-2 |
| ITF M15 Novi Sad | 2021/07/25 12:00 | Gabriel Donev v Besir Durguti | 6-1,6-1 |
| ITF M15 Sofia | 2021/07/09 08:30 | Gabriel Donev v Alexander Weis | 6-4,3-6,6-7 |
| ITF M15 Antalya | 2021/06/22 07:00 | Vladimir Korolev v Filip Duda | 6-3,2-6,10-4 |
| ITF M15 Antalya | 2021/06/21 11:35 | Dian Nedev v Filip Duda | 4-6,2-6 |
| ITF M15 Antalya | 2021/06/20 07:00 | Kaya Arinc v Filip Duda | 0-6,4-6 |
| ITF M15 Antalya | 2021/06/15 07:30 | Tadeas Paroulek v Filip Duda | 6-2,6-4 |
| ITF M15 Antalya | 2021/06/14 13:45 | Daiki Yoshimura v Filip Duda | 3-6,6-7 |
| ITF M15 Antalya | 2021/06/13 07:30 | Farzin Danny Amiri v Filip Duda | 6-3,4-6,6-10 |
| ITF M25 Most | 2021/05/26 08:00 | Filip Duda v Pavel Nejedly | 4-6,2-6 |
| ITF M25 Most | 2021/05/25 09:35 | Filip Duda v Stepan Mruzek | 2-6,6-4,10-5 |