Stadium: Court 1 Round: 25 Ground: Clay
| Polska - National Tour | 2020/07/26 09:50 | Piotr Grynkowski v Daniel Michalski | 4-6,3-6 |
| ITF - Gdynia M15 | 2021/08/13 12:00 | Daniel Michalski v Fabian Marozsan | 4-6,3-6 |
| ITF - Gdynia M15 | 2021/08/12 10:30 | Daniel Michalski v Michal Dembek | 7-6,4-6,6-3 |
| ITF - Gdynia M15 | 2021/08/11 12:40 | Daniel Michalski v Igor Marcondes | 6-2,6-3 |
| ITF - Grodzisk Mazowiecki M25 | 2021/08/05 13:10 | Adam Pavlasek v Daniel Michalski | 7-5,6-4 |
| ITF - Grodzisk Mazowiecki M25 | 2021/08/05 07:00 | Aleksander Orlikowski v Daniel Michalski | 2-6,1-6 |
| Challenger Poznań | 2021/07/27 11:50 | Daniel Michalski v Botic Van De Zandschulp | 2-6,3-6 |
| Polska - National Tour | 2021/07/15 10:35 | Daniel Michalski v Kacper Zuk | 2-6,4-6 |
| Polska - National Tour | 2021/07/14 11:50 | Maciej Rajski v Daniel Michalski | 0-6,5-7 |
| ITF - Grodzisk Mazowiecki M25 | 2021/08/03 09:00 | Piotr Grynkowski v Pawel Juszczak | 2-6,2-6 |
| ITF - Wrocław M25 | 2021/06/28 11:00 | Piotr Grynkowski v Maciej Rajski | 6-7,4-6 |
| ITF - Wrocław M25 | 2021/06/27 15:30 | Luca Castelnuovo v Piotr Grynkowski | 6-4,6-7,7-10 |
| ITF - Tbilisi M15 | 2021/05/17 06:00 | Piotr Grynkowski v Christian Sigsgaard | 3-6,3-6 |
| ITF - Tbilisi M15 | 2021/05/17 05:30 | Piotr Grynkowski v David Chelidze | 4-6,6-4,10-7 |
| ITF - Cairo M15 | 2021/04/14 12:30 | Francesco Passaro v Piotr Grynkowski | 7-5,6-1 |
| ITF - Cairo M15 | 2021/04/13 12:30 | Piotr Grynkowski v Andrea Gola | 6-3,4-6,10-2 |
| ITF - Bratysława M15 | 2021/03/09 12:00 | Piotr Grynkowski v Edward Hubner | 2-6,2-6 |