Stadium: Court 1 Round: 26 Ground: Clay
| ITF M15 Łódź | 2021/08/18 11:40 | Daniel Michalski v Piotr Grynkowski | 6-1,6-1 |
| ITF M15 Gdynia | 2021/08/13 12:00 | Daniel Michalski v Fabian Marozsan | 4-6,3-6 |
| ITF M15 Gdynia | 2021/08/12 10:30 | Daniel Michalski v Michal Dembek | 7-6,4-6,6-3 |
| ITF M15 Gdynia | 2021/08/11 12:40 | Daniel Michalski v Igor Marcondes | 6-2,6-3 |
| ITF M25 Grodzisk Mazowiecki | 2021/08/05 13:10 | Adam Pavlasek v Daniel Michalski | 7-5,6-4 |
| ITF M25 Grodzisk Mazowiecki | 2021/08/05 07:00 | Aleksander Orlikowski v Daniel Michalski | 2-6,1-6 |
| Challenger - Poznan | 2021/07/27 11:50 | Daniel Michalski v Botic Van De Zandschulp | 2-6,3-6 |
| Polish National Tour | 2021/07/15 10:35 | Daniel Michalski v Kacper Zuk | 2-6,4-6 |
| ITF M15 Łódź | 2021/08/18 09:30 | Roman Andres Burruchaga v Szymon Kielan | 6-7,3-6 |
| ITF M15 Gdynia | 2021/08/12 10:25 | Szymon Kielan v Alexis Musialek | 3-6,4-6 |
| ITF M15 Gdynia | 2021/08/11 14:25 | Luke Johnson v Szymon Kielan | 1-6,6-7 |
| ITF M25 Grodzisk Mazowiecki | 2021/08/04 17:10 | David Poljak v Szymon Kielan | 7-5,6-3 |
| Polish National Tour | 2021/07/11 10:00 | Kamil Majchrzak v Szymon Kielan | 6-1,7-6 |
| ITF M25 Wroclaw | 2021/06/30 13:15 | Gonzalo Lama v Szymon Kielan | 6-1,6-2 |
| ITF M25 Wroclaw | 2021/06/29 08:00 | Szymon Kielan v Mateusz Terczynski | 6-3,6-2 |
| ITF M25 Wroclaw | 2021/06/28 11:00 | Lewie Lane v Szymon Kielan | 3-6,0-6 |