| UTR Pro Tennis Series Brasov | 2021/10/25 07:00 | Dragos Constantin Ignat v Dan Alexandru Tomescu | 2-6,0-5 |
| ITF M15 Antalya | 2021/10/21 08:30 | Gergely Madarasz v Dan Alexandru Tomescu | 6-3,6-0 |
| ITF M15 Antalya | 2021/10/20 08:40 | Felix Gill v Dan Alexandru Tomescu | 3-6,6-4,4-6 |
| ITF M15 Antalya | 2021/10/19 09:20 | Dan Alexandru Tomescu v Gian Marco Ortenzi | 5-7,7-6,11-9 |
| ITF M15 Antalya | 2021/10/18 10:05 | Dan Alexandru Tomescu v Kristof Minarik | 6-1,6-1 |
| ITF M15 Antalya | 2021/10/17 07:00 | Dan Alexandru Tomescu v Andrea Del Federico | 6-3,6-3 |
| ITF M15 Antalya | 2021/10/13 08:25 | Savriyan Danilov v Dan Alexandru Tomescu | 7-6,3-6,6-4 |
| ITF M15 Sozopol | 2021/10/06 07:00 | Dan Alexandru Tomescu v Yannik Steinegger | 3-6,6-7 |
| Challenger Lisbon | 2021/09/27 15:10 | Igor Sijsling v Andrea Pellegrino | 0-6,4-6 |
| Challenger Braga | 2021/09/21 09:00 | Igor Sijsling v Michael Vrbensky | 1-6,4-6 |
| Challenger Prague | 2021/08/27 09:00 | Franco Agamenone v Igor Sijsling | 6-3,6-0 |
| Challenger Prague | 2021/08/26 10:00 | Igor Sijsling v Kaichi Uchida | 7-5,6-3 |
| Challenger Prague | 2021/08/24 13:45 | Daniel Siniakov v Igor Sijsling | 4-6,3-6 |
| Challenger Segovia | 2021/07/27 14:25 | Igor Sijsling v Teymuraz Gabashvili | 1-6,3-6 |
| Challenger Pozoblanco | 2021/07/22 16:00 | Tim Van Rijthoven v Igor Sijsling | 6-4,6-4 |
| Challenger Iasi | 2021/07/12 11:50 | Felipe Meligeni Rodrigues Alves v Igor Sijsling | 7-5,6-2 |