Ground: Clay
| ITF M15 Antalya | 2025/04/23 09:00 | Marcel Zielinski v Mert Naci Turker | 4-6,2-6 |
| ITF M15 Antalya | 2025/04/17 08:30 | Marcel Zielinski v Ryan Nijboer | 4-6,4-6 |
| ITF M15 Antalya | 2025/04/16 08:30 | Maxwell Exsted v Marcel Zielinski | 5-7,4-6 |
| ITF M15 Alaminos | 2025/03/13 07:30 | Pablo Masjuan Ginel v Marcel Zielinski | 7-6,6-4 |
| ITF M15 Alaminos | 2025/03/12 11:00 | Marcel Zielinski v Adrian Oetzbach | 6-3,4-6,7-5 |
| ITF M15 Valencia | 2025/02/12 15:17 | Max Alcala Gurri v Marcel Zielinski | 6-3,5-3 |
| ITF M15 Valencia | 2024/11/11 09:00 | Marcel Zielinski v Anas Mazdrashki | 2-6,5-7 |
| ITF M15 Valencia | 2024/11/10 13:00 | Marcel Zielinski v Pere Prat Turro | 7-6,6-3 |