Stadium: Court 4 Round: 25 Ground: Clay
| ITF M25 - Lodz | 2023/08/09 09:20 | Alex M Pujolras v Adam Majchrzak | 6-1,6-7,6-2 |
| ITF M15 - Wrocław | 2023/06/28 08:00 | Adam Majchrzak v Michal Mikula | 2-6,3-6 |
| ITF M15 - Łódź | 2022/07/27 09:30 | Maks Kasnikowski v Adam Majchrzak | 6-4,6-0 |
| ITF M15 - Hoei | 2023/08/25 08:00 | Marcel Zielinski v Felix Corwin | 6-1,1-6,3-6 |
| ITF M15 - Hoei | 2023/08/23 14:10 | Marcel Zielinski v Lautaro Agustin Falabella | 6-3,6-4 |
| ITF - M15 Frankfurt Am Main | 2023/08/09 13:00 | Jakob Schnaitter v Marcel Zielinski | 6-7,6-2,6-2 |
| ITF - M15 Eindhoven | 2023/08/03 11:20 | Elmer Moller v Marcel Zielinski | 6-3,6-1 |
| ITF - M15 Eindhoven | 2023/08/01 15:20 | Alexis Boureau v Marcel Zielinski | 1-6,1-6 |
| ITF - M25 Esch/Alzette | 2023/07/13 14:30 | Marcel Zielinski v Brian Bozemoj | 6-2,6-4 |
| ITF - M25 Esch/Alzette | 2023/07/12 11:35 | Marcel Zielinski v Boris Fassbender | 6-3,6-1 |
| ITF M15 Sofia | 2023/07/06 08:10 | Matej Dodig v Marcel Zielinski | 6-4,6-2 |