Stadium: Court 1 Round: 25 Ground: Hardcourt indoor
| ITF M15 Sofia | 2023/07/06 08:10 | Matej Dodig v Marcel Zielinski | 6-4,6-2 |
| ITF M15 Sofia | 2023/07/05 09:45 | Alessandro Ingarao v Marcel Zielinski | 0-6,3-6 |
| ITF M15 Kamen | 2023/06/28 10:50 | Matyas Cerny v Marcel Zielinski | 6-4,6-4 |
| ITF M15 Saarlouis | 2023/06/23 16:30 | Marcel Zielinski v Jeffrey Von Der Schulenburg | 6-7,6-2,1-6 |
| ITF M15 Saarlouis | 2023/06/22 09:30 | Marcel Zielinski v Tim Heger | 6-0,6-3 |
| 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 M25 Esch/Alzette | 2023/07/10 16:20 | Boris Fassbender v Loris Pourroy | 7-6,7-5 |
| ITF M25 Esch/Alzette | 2023/07/10 13:15 | Boris Fassbender v Charles Berna | 6-2,6-2 |
| ITF M25 Arlon | 2023/06/28 07:50 | Boris Fassbender v Sebastian Fanselow | 2-6,3-6 |
| ITF M25 Arlon | 2023/06/27 11:20 | Boris Fassbender v Aaron Gil Garcia | 6-4,2-6,10-4 |
| ITF M25 Arlon | 2023/06/26 16:35 | Boris Fassbender v Dylan Leigniel | 6-1,6-0 |
| ITF M15 Saarlouis | 2023/06/19 09:30 | Boris Fassbender v Collin Altamirano | 2-6,7-6,8-10 |
| ITF M25 Saint Dizier | 2023/03/29 09:35 | Boris Fassbender v David Jorda Sanchis | 3-6,6-3,4-6 |
| ITF M15 Villers Les Nancy | 2022/11/06 13:25 | Dan Added v Boris Fassbender | 6-4,5-7,6-2 |