Stadium: Court 3 Round: 26 Ground: Clay
| ITF M15 Saarlouis | 2023/06/21 09:25 | Mika Brunold v Marcel Zielinski | 3-6,1-6 |
| ITF M15 Meerbusch | 2023/04/27 08:55 | Marcel Zielinski v Liam Gavrielides | 6-7,1-6 |
| ITF M15 Meerbusch | 2023/04/26 09:00 | Marcel Zielinski v John Sperle | 7-6,7-5 |
| ITF M15 Telde | 2023/04/23 09:00 | Marcel Zielinski v Alejandro Manzanera Pertusa | 4-6,6-7 |
| ITF M15 Telde | 2023/04/22 09:00 | Kai Lemstra v Marcel Zielinski | 2-6,4-6 |
| ITF M15 Telde | 2023/04/21 09:00 | Marcel Zielinski v Martin Cuevas | 6-4,6-1 |
| ITF M15 Telde | 2023/04/20 12:30 | Jorge Martinez Martinez v Marcel Zielinski | 3-6,2-6 |
| ITF M15 Telde | 2023/04/18 08:00 | Marcel Zielinski v Benjamin Winter Lopez | 3-6,6-2,6-4 |
| ITF M15 Saarlouis | 2023/06/21 11:30 | Tim Heger v Konstantin Cucka | 6-2,6-0 |
| ITF M15 Litija | 2023/06/14 07:30 | Sebastian Prechtel v Tim Heger | 6-3,6-4 |
| ITF M15 Litija | 2023/06/13 07:00 | Corey Gaal v Tim Heger | 6-3,6-7,8-10 |
| ITF M15 Litija | 2023/06/12 07:00 | Kaj Quirijns v Tim Heger | 3-6,4-6 |
| ITF M15 Warmbad-Villach | 2023/05/22 11:10 | Tim Heger v Noah Schlagenhauf | 5-7,6-7 |
| ITF M15 Warmbad-Villach | 2023/05/21 12:00 | Pietro Pampanin v Tim Heger | 4-6,4-6 |
| ITF M15 Krsko | 2023/05/17 08:00 | Tomas Lanik v Tim Heger | 6-2,6-3 |
| ITF M15 Krsko | 2023/05/15 12:30 | Andrej Krajcik v Tim Heger | 1-6,1-6 |