Estádio: Court 3 Round: 25 Ground: Hardcourt outdoor
| ITF - M15 Łódź | 2021/08/18 11:40 | Daniel Michalski v Piotr Grynkowski | 6-1,6-1 |
| ITF - M25 Grodzisk Mazowiecki | 2021/08/03 09:00 | Piotr Grynkowski v Pawel Juszczak | 2-6,2-6 |
| ITF - M25 Wrocław | 2021/06/28 11:00 | Piotr Grynkowski v Maciej Rajski | 6-7,4-6 |
| ITF - M25 Wrocław | 2021/06/27 15:30 | Luca Castelnuovo v Piotr Grynkowski | 6-4,6-7,7-10 |
| ITF - M15 Tbilisi | 2021/05/17 06:00 | Piotr Grynkowski v Christian Sigsgaard | 3-6,3-6 |
| ITF - M15 Tbilisi | 2021/05/17 05:30 | Piotr Grynkowski v David Chelidze | 4-6,6-4,10-7 |
| ITF - M15 Cairo | 2021/04/14 12:30 | Francesco Passaro v Piotr Grynkowski | 7-5,6-1 |
| ITF - M15 Cairo | 2021/04/13 12:30 | Piotr Grynkowski v Andrea Gola | 6-3,4-6,10-2 |
| ITF - M15 Monastir | 2021/12/04 08:30 | Andrew Paulson v Stuart Parker | 2-6,2-6 |
| ITF - M15 Monastir | 2021/12/03 10:15 | Andrew Paulson v Matas Vasiliauskas | 6-1,6-2 |
| ITF - M15 Monastir | 2021/12/02 12:30 | Andrew Paulson v Kasidit Samrej | 7-6,7-5 |
| ITF - M15 Ostrava | 2021/11/28 09:00 | Andrew Paulson v Marvin Moeller | 6-3,7-6 |
| ITF - M15 Ostrava | 2021/11/27 09:30 | Andrew Paulson v Remy Bertola | 6-3,6-4 |
| ITF - M15 Ostrava | 2021/11/26 09:30 | David Poljak v Andrew Paulson | 6-4,6-7,3-6 |
| ITF - M15 Ostrava | 2021/11/23 09:00 | Andrew Paulson v Timo Stodder | 6-2,6-2 |
| ITF - M15 Opava | 2021/11/19 09:00 | David Poljak v Andrew Paulson | 6-2,4-6,7-6 |