Estadio: Court 5 Round: 44 Ground: Clay
| ITF M25 Nur-Sultán | 2021/07/09 07:00 | Petr Bar Biryukov v Beibit Zhukayev | 4-6,3-6 |
| ITF M25 Nur-Sultán | 2021/07/08 05:00 | Petr Bar Biryukov v Vladyslav Manafov | 3-6,6-2,6-3 |
| ITF M25 Nur-Sultán | 2021/07/07 07:00 | Kirill Kolganov v Petr Bar Biryukov | 2-6,1-6 |
| ITF M25 Nur-Sultán | 2021/07/06 05:55 | Petr Bar Biryukov v Danil Ozernoy | 6-3,7-6 |
| ITF 15 Antalya | 2021/06/27 06:30 | Inigo G Olasagasti v Petr Bar Biryukov | 7-6,1-6,10-5 |
| ITF M15 Shymkent | 2021/06/02 11:45 | Petr Bar Biryukov v Yan Bondarevskiy | 3-6,2-6 |
| ITF M15 Shymkent | 2021/06/01 09:20 | Antonio Campo v Petr Bar Biryukov | 4-6,6-3,10-7 |
| ITF M15 Shymkent | 2021/05/31 06:35 | Alexey Dubinin v Petr Bar Biryukov | 2-6,2-6 |
| ITF M25 Telfs | 2021/07/16 10:00 | Kirill Kivattsev v Ondrej Horak | 6-2,6-2 |
| ITF M25 Telfs | 2021/07/14 07:55 | George Botezan v Ondrej Horak | 6-4,2-6,5-7 |
| ITF M25 Telfs | 2021/07/13 07:30 | Neil Oberleitner v Ondrej Horak | 4-6,4-6 |
| ITF M25 Telfs | 2021/07/12 07:55 | Ondrej Horak v Samuel Puskar | 6-3,6-4 |
| ITF M25 Wroclaw | 2021/06/28 10:00 | Daniel Dutra Da Silva v Ondrej Horak | 3-6,0-6 |
| ITF M15 Skopje | 2021/06/07 08:30 | Leonid Sheyngezikht v Ondrej Horak | 6-0,7-5 |
| ITF M15 Skopje | 2021/06/06 09:00 | Ondrej Horak v Luigi Sorrentino | 6-0,1-6,11-9 |
| ITF M15 Skopje | 2021/05/30 09:30 | Ondrej Horak v Viktor Jovic | 4-6,3-6 |