Round: 44 Ground: Clay
| Challenger Sopot Qual | 2018/07/30 15:15 | Dimitar Kuzmanov v Jan Zielinski | 6-0,6-1 |
| Challenger Sopot Qual | 2018/07/30 09:00 | Jan Zielinski v Cristian Rodriguez | 7-5,6-3 |
| Challenger Sopot Qual | 2018/07/28 12:05 | Yann Wojcik v Jan Zielinski | 2-6,6-2,3-6 |
| ITF Poland F3 Qual | 2017/06/25 08:00 | Dante Gennaro v Jan Zielinski | 6-3,6-1 |
| ITF Poland F2 | 2017/06/17 08:00 | Filip Bergevi v Jan Zielinski | 4-6,7-6,6-3 |
| ITF Poland F1 | 2017/06/12 13:45 | Jan Zielinski v Zdenek Kolar | 4-6,3-6 |
| ITF Estonia F1 | 2016/07/25 22:00 | Dmitry Mnushkin v Jan Zielinski | 4-6,7-6,7-5 |
| ITF Lithuania F1 | 2016/07/18 08:00 | Ivan Davydov v Jan Zielinski | 3-6,6-1,7-5 |