Stadium: Court 5 Round: 62 Ground: Hardcourt outdoor
| ITF M15 Sharm El Sheikh | 2021/10/07 08:00 | Lorenzo Bocchi v Szymon Kielan | 7-6,6-1 |
| ITF M15 Sharm El Sheikh | 2021/10/06 08:00 | Szymon Kielan v Alexandros Skorilas | 6-4,6-2 |
| ITF M15 Vyshkovo | 2021/09/21 07:00 | Szymon Kielan v Artem Smirnov | 6-4,3-6,3-6 |
| Challenger Szczecin | 2021/09/12 09:00 | Szymon Kielan v Alex Rybakov | 2-6,6-2,3-6 |
| Challenger Warsaw | 2021/08/26 13:00 | Lucas Miedler v Szymon Kielan | 7-5,6-4 |
| Challenger Warsaw | 2021/08/25 08:00 | Szymon Kielan v Goncalo Oliveira | 7-5,6-0 |
| ITF M15 Lodz | 2021/08/19 10:30 | Daniel Michalski v Szymon Kielan | 3-6,7-5,6-3 |
| ITF M15 Lodz | 2021/08/18 09:30 | Roman Andres Burruchaga v Szymon Kielan | 6-7,3-6 |
| ITF M15 Sharm El Sheikh | 2021/10/10 09:30 | Dean Cooper Kirby v Ali Zaghloul | 6-0,6-1 |