| ITF - M25 Ricany | 2021/08/29 12:00 | Dominik Langmajer v Martin Machala | 3-6,3-6 |
| ITF - M25 Poznan | 2021/08/22 08:00 | Dominik Langmajer v Marcelo Zormann | 4-6,1-6 |
| ITF - M15 Lodz | 2021/08/15 11:00 | Omar Brigida v Dominik Langmajer | 6-1,6-4 |
| ITF - M15 Gdynia | 2021/08/08 08:00 | Olaf Pieczkowski v Dominik Langmajer | 6-2,6-1 |
| ITF - M25 Grodzisk Mazowiecki | 2021/08/01 09:55 | Dominik Langmajer v Yujiro Onuma | 3-6,3-6 |
| ITF - M15 Castelo Branco | 2021/07/26 11:00 | Adan Freire Da Silva v Dominik Langmajer | 6-3,6-2 |
| ITF - M15 Castelo Branco | 2021/07/25 16:00 | Mark Owen Endler v Dominik Langmajer | 3-6,6-2,5-10 |
| ITF - M25 Wroclaw | 2021/06/27 14:00 | Dominik Langmajer v Mateusz Terczynski | 1-6,3-6 |
| UTR Pro Tennis Series - Ricany | 2021/09/09 07:30 | Dominik Suc v Stefanos Sakellaridis | 5-7,6-7 |
| UTR Pro Tennis Series - Ricany | 2021/09/07 09:00 | Filip Duda v Stefanos Sakellaridis | 4-6,6-4,5-2 |
| ITF - M15 Bad Waltersdorf | 2021/08/31 07:00 | Luigi Sorrentino v Stefanos Sakellaridis | 6-0,5-7,10-7 |
| ITF - M15 Bad Waltersdorf | 2021/08/22 09:00 | Joshua Peck v Stefanos Sakellaridis | 1-6,6-3,11-9 |
| ITF - M15 Warmbad-Villach | 2021/08/17 07:30 | Lorenzo Vatteroni v Stefanos Sakellaridis | 7-6,6-2 |
| ITF - M15 Warmbad-Villach | 2021/08/16 12:30 | Leon Benedict v Stefanos Sakellaridis | 4-6,3-6 |
| ITF - M15 Novi Sad | 2021/08/01 14:00 | Stefanos Sakellaridis v Lukas Palovic | 4-6,1-6 |
| ITF - M25 Kottingbrunn | 2021/07/18 07:30 | Stefanos Sakellaridis v Samuel Paulovcak | 1-6,4-6 |