Stadium: Court 8 Round: 54 Ground: Clay
| ITF M25 Grodzisk Mazowiecki | 2021/08/02 11:00 | Lars Aregger v Piotr Galus | 3-6,1-6 |
| ITF M25 Most | 2021/05/24 08:00 | Benedikt Emesz v Lars Aregger | 7-6,6-0 |
| ITF M25 Most | 2021/05/23 08:00 | Lars Aregger v Fred Olivier Schommer | 3-6,6-1,10-8 |
| ITF M25 Kottingbrunn | 2021/07/19 10:35 | Jakub Kroslak v Peter Makk | 4-6,6-3,6-10 |
| ITF M25 Kottingbrunn | 2021/07/18 07:30 | Roman Postolka v Jakub Kroslak | 4-6,3-6 |
| ITF M15 Poprad | 2021/07/04 11:00 | Jakub Kroslak v Mateusz Terczynski | 6-2,6-7,9-11 |
| ITF M15 Monastir | 2021/03/28 09:00 | Aleksandr Kalinin v Jakub Kroslak | 7-5,7-6 |
| ITF M15 Monastir | 2021/03/22 10:00 | Jakub Kroslak v Aristotelis Thanos | 4-6,2-6 |
| ITF M15 Monastir | 2021/03/21 16:00 | Jakub Kroslak v Tushar Sharma | 6-1,6-1 |
| ITF M15 Bratislava | 2021/03/09 09:00 | Jakub Kroslak v Luca Van Assche | 2-6,1-6 |
| ITF M15 Bratislava | 2021/03/08 15:00 | Jakub Kroslak v Radovan Michalik | 6-1,1-6,10-7 |