| UTR Pro Tennis Series Amsterdam | 2021/11/06 12:00 | Deney Wassermann v Guy Den Heijer | 2-6,5-6 |
| UTR Pro Tennis Series Amsterdam | 2021/12/10 08:25 | Rob Van Den Berg v Guy Den Heijer | 3-6,2-6 |
| 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 Irákleio | 2021/11/24 08:55 | Guy Den Heijer v Arthur Fery | 6-7,2-6 |
| ITF M15 Irákleio | 2021/11/18 10:25 | Guy Den Heijer v Nicholas David Ionel | 1-6,7-5,1-6 |
| ITF M15 Irákleio | 2021/11/17 13:25 | Sergis Kyratzis v Guy Den Heijer | 6-0,4-6,4-6 |
| ITF M15 Irákleio | 2021/11/11 07:00 | Guy Den Heijer v Alec Deckers | 4-6,6-7 |
| UTR Pro Tennis Series Amsterdam | 2021/12/10 08:30 | Deney Wassermann v Niklas Koch | 6-2,6-3 |
| UTR Pro Tennis Series Amsterdam | 2021/12/08 08:30 | Deney Wassermann v Miko Wassermann | 7-6,4-6,6-2 |
| UTR Pro Tennis Series Amsterdam | 2021/12/07 08:30 | Deney Wassermann v Ryan Nijboer | 6-0,5-1 |
| UTR Pro Tennis Series Amsterdam | 2021/12/06 10:15 | Yan Sabanin v Deney Wassermann | 3-6,6-6 |
| ITF M15 Irákleio | 2021/11/22 08:00 | Deney Wassermann v Elmer Moller | 1-6,4-6 |
| ITF M15 Irákleio | 2021/11/15 08:00 | Deney Wassermann v Andrei Cuceu | 6-2,6-1 |
| UTR Pro Tennis Series Amsterdam | 2021/11/06 12:00 | Deney Wassermann v Guy Den Heijer | 2-6,5-6 |
| UTR Pro Tennis Series Amsterdam | 2021/11/05 12:00 | Michiel de Krom v Deney Wassermann | 2-6,3-6 |