| ITF Poland F3 | 2016/06/07 09:20 | Dembek, Michal v Zielinski, Jan | 2-6,6-4,2-6 |
| Marbello Cup Exhibition Series | 2020/06/02 13:30 | Daniel Michalski v Zielinski, Jan | 6-0,5-7,8-10 |
| Marbello Cup Exhibition Series | 2020/06/02 07:00 | Zielinski, Jan v Terczynski, Mateusz | 4-6,6-3,10-6 |
| ITF - M25 Sunderland | 2020/02/24 11:40 | Zielinski, Jan v George Houghton | 4-6,6-3,7-10 |
| ITF - M25 Sunderland | 2020/02/23 13:05 | Zielinski, Jan v Meehan, Harry David | 4-6,6-4,11-9 |
| ITF M25 Glasgow | 2020/02/19 10:00 | Zielinski, Jan v Antoine Bellier | 4-6,4-6 |
| ITF M25 Glasgow | 2020/02/17 14:25 | Zielinski, Jan v Hendrik Jebens | 4-6,2-6 |
| ITF M25 Glasgow | 2020/02/16 17:40 | Zielinski, Jan v Mcintosh, Euan | 6-4,6-2 |
| Barnstaple, Singles Qualifying M-ITF-GBR-01A | 2020/02/13 11:20 | Kacper Zuk v Zielinski, Jan | 3-6,6-0,6-1 |
| Marbello Cup Exhibition Series | 2020/06/02 17:15 | Dembek, Michal v Kolasinski, Filip | 4-6,6-2,10-7 |
| Marbello Cup Exhibition Series | 2020/06/02 11:15 | Maciej Rajski v Dembek, Michal | 6-3,3-6,17-15 |
| ITF M15 Loule | 2020/03/10 11:35 | Turchetti, Nicolo v Dembek, Michal | 6-4,4-6,6-4 |
| ITF M15 Faro | 2020/03/04 10:00 | Mertens, Yannick v Dembek, Michal | 6-2,7-5 |
| ITF - M15 Héraklion | 2020/02/12 09:30 | Dembek, Michal v Petros Tsitsipas | 7-5,2-6,6-7 |
| ITF - M15 Antalya | 2019/12/17 07:00 | Dembek, Michal v Nedelko, Ivan | 7-6,5-7,2-6 |
| Antalya, Qualifications Simples M-ITF-TUR-33A | 2019/12/09 07:00 | Dembek, Michal v Igor Saveljic | 1-6,6-7 |
| ITF - M15 Monastir | 2019/11/27 12:40 | Dembek, Michal v Benjamin Lock | 6-7,2-6 |