Stadium: Court 4 Round: 19 Ground: Clay
| Challenger Prostejov | 2021/06/14 08:30 | Johannes Haerteis v David Poljak | 5-7,3-6 |
| Challenger Prostejov | 2021/06/13 09:00 | David Poljak v Sem Verbeek | 6-3,6-3 |
| ITF M15 Monastir | 2021/05/25 08:30 | David Poljak v Naoki Nakagawa | 6-7,7-6,1-6 |
| ITF M15 Monastir | 2021/05/20 08:25 | David Poljak v Jeremy Beale | 6-7,1-6 |
| ITF M15 Monastir | 2021/05/18 10:20 | David Poljak v Louis Tessa | 7-6,6-4 |
| Challenger Salinas 2 | 2021/04/27 14:30 | Gonzalo Villanueva v David Poljak | 5-7,7-6,7-6 |
| Challenger Salinas 2 | 2021/04/26 18:35 | Miguel M Larrea v David Poljak | 3-6,0-6 |
| Challenger Salinas | 2021/04/18 15:00 | Tak Khunn Wang v David Poljak | 6-3,6-3 |
| Challenger Forli | 2021/06/14 09:30 | Lucas Gerch v Elmar Ejupovic | 4-6,6-4,7-6 |
| Challenger Forli | 2021/06/13 09:45 | Alessandro Bega v Lucas Gerch | 3-6,1-6 |
| ITF M15 Antalya | 2021/05/28 08:20 | Pol Martin Tiffon v Lucas Gerch | 7-5,6-3 |
| ITF M15 Antalya | 2021/05/27 10:10 | Paul Woerner v Lucas Gerch | 7-5,6-7,3-6 |
| ITF M15 Antalya | 2021/05/26 12:00 | Giorgio Tabacco v Lucas Gerch | 2-6,3-6 |
| ITF M15 Antalya | 2021/05/20 07:30 | Lucas Gerch v Mariano Navone | 3-6,6-4,2-6 |
| ITF M15 Antalya | 2021/05/19 07:25 | Lucas Gerch v Fermin Tenti | 6-3,6-4 |
| ITF M15 Troisdorf | 2021/05/14 12:25 | Michael Geerts v Lucas Gerch | 7-5,6-4 |