| UTR Pro Tennis Series Amsterdam | 2021/12/09 09:00 | Rob Van Den Berg v Max Van Nunen | 7-5,5-7,6-4 |
| UTR Pro Tennis Series Amsterdam | 2021/12/08 07:00 | Jip Van Assendelft v Rob Van Den Berg | 4-6,6-4,6-1 |
| UTR Pro Tennis Series Amsterdam | 2021/12/07 08:30 | Michiel de Krom v Rob Van Den Berg | 5-7,6-3,5-2 |
| UTR Pro Tennis Series Amsterdam | 2021/12/09 11:50 | Jip Van Assendelft v Guy Den Heijer | 2-6,2-6 |
| UTR Pro Tennis Series Amsterdam | 2021/12/08 10:00 | Michiel de Krom v Guy Den Heijer | 3-6,3-5 |
| UTR Pro Tennis Series Amsterdam | 2021/12/06 07:00 | Jannis Kahlke v Guy Den Heijer | 7-6,5-7,3-5 |
| ITF M15 Heraklion | 2021/11/24 08:55 | Guy Den Heijer v Arthur Fery | 6-7,2-6 |
| ITF M15 Heraklion | 2021/11/18 10:25 | Guy Den Heijer v Nicholas David Ionel | 1-6,7-5,1-6 |
| ITF M15 Heraklion | 2021/11/17 13:25 | Sergis Kyratzis v Guy Den Heijer | 6-0,4-6,4-6 |
| ITF M15 Heraklion | 2021/11/11 07:00 | Guy Den Heijer v Alec Deckers | 4-6,6-7 |
| ITF M15 Heraklion | 2021/11/10 07:00 | Guy Den Heijer v Max Houkes | 7-6,6-3 |