Stadium: Court 2 Round: 62 Ground: Clay
| 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 |
| ITF M25 Most | 2021/05/23 14:00 | Martin Damm v Ondrej Horak | 7-5,6-4 |
| ITF M25 Jablonec Nad Nisou | 2021/05/17 07:30 | Ondrej Horak v Tomas Papik | 1-6,4-6 |
| ITF M25 Jablonec Nad Nisou | 2021/05/16 08:30 | George Loffhagen v Ondrej Horak | 5-7,1-6 |
| ITF M25 Prague | 2021/05/10 08:00 | Jan Satral v Ondrej Horak | 6-1,6-2 |
| ITF M15 Poprad | 2021/07/07 11:30 | Julien Penzlin v Samuel Puskar | 6-4,7-6 |
| ITF M15 Poprad | 2021/07/05 08:00 | Samuel Puskar v Kristof Minarik | 6-3,7-6 |
| ITF M15 Poprad | 2021/07/04 08:00 | Samuel Puskar v Ondrej Valek | 7-5,6-1 |
| ITF M25 Wroclaw | 2021/06/27 15:30 | Samuel Puskar v Carl Soderlund | 6-4,1-6,8-10 |
| ITF M15 Skopje | 2021/06/06 07:30 | Samuel Puskar v Michele Vianello | 6-4,0-6,6-10 |
| ITF M15 Monastir | 2021/04/18 13:00 | Remy Bertola v Samuel Puskar | 6-3,6-4 |
| ITF M15 Monastir | 2021/04/12 09:00 | Samuel Puskar v Michal Mikula | 2-6,1-6 |
| ITF M15 Monastir | 2021/04/11 12:00 | Marius Ruzgas v Samuel Puskar | 4-6,6-7 |