| UTR Pro Tennis Series - Dubai | 2022/01/10 04:30 | Dan Alexandru Tomescu v Kai Lemstra | 2-6,4-6 |
| UTR Pro Tennis Series - Dubai | 2022/01/08 04:30 | Kai Lemstra v Simon Roberts | 0-0 |
| UTR Pro Tennis Series - Dubai | 2022/01/07 04:30 | Michael Zhu v Kai Lemstra | 7-6,6-2 |
| UTR Pro Tennis Series - Dubai | 2022/01/06 06:00 | David Pichler v Kai Lemstra | 6-4,4-6,4-6 |
| UTR Pro Tennis Series - Dubai | 2022/01/05 07:30 | Mircea-Alexandru Jecan v Kai Lemstra | 6-4,7-5 |
| UTR Pro Tennis Series - Dubai | 2022/01/03 10:50 | Jonathan Eysseric v Kai Lemstra | 6-3,6-1 |
| German Championship | 2021/12/07 15:00 | Kai Lemstra v Tom Schonenberg | 3-6,0-6 |
| ITF M15 - Heraklion | 2021/11/23 07:00 | Nicholas David Ionel v Kai Lemstra | 3-6,7-5,10-4 |
| ITF M25 - Hamborg | 2021/10/17 17:15 | Daniel Little v Mateusz Terczynski | 6-4,6-0 |
| ITF M25 - Hamborg | 2021/10/17 12:25 | Tom Clavel v Mateusz Terczynski | 4-6,1-6 |
| ITF M25 - Prag | 2021/10/03 10:00 | Samuel Paulovcak v Mateusz Terczynski | 4-6,6-3,10-8 |
| Polen - National Tour | 2021/07/13 11:50 | Mateusz Terczynski v Daniel Michalski | 2-6,1-6 |
| ITF M15 - Poprad | 2021/07/05 08:00 | Illya Beloborodko v Mateusz Terczynski | 6-4,6-2 |
| ITF M15 - Poprad | 2021/07/04 11:00 | Jakub Kroslak v Mateusz Terczynski | 6-2,6-7,9-11 |
| ITF M25 - Wroclaw | 2021/06/29 08:00 | Szymon Kielan v Mateusz Terczynski | 6-3,6-2 |
| ITF M25 - Wroclaw | 2021/06/28 11:00 | Mateusz Terczynski v Lukas Palovic | 6-3,6-1 |