| ITF - M15 Doha | 2019/03/05 12:00 | Michiel de Krom v Guy Den Heijer | 5-7,6-3,9-11 |
| 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 | 2021/12/06 07:00 | Jip Van Assendelft v Michiel de Krom | 2-6,6-2,1-6 |
| UTR Pro Tennis Series - Barcelona | 2021/11/28 09:30 | Michiel de Krom v Vlad Cristian Breazu | 6-1,4-6,6-1 |
| UTR Pro Tennis Series - Barcelona | 2021/11/27 11:00 | Michiel de Krom v Alvaro Bueno Gil | 6-4,6-3 |
| UTR Pro Tennis Series - Barcelona | 2021/11/26 09:30 | Michiel de Krom v Volodymyr Uzhylovskyi | 6-0,6-2 |
| UTR Pro Tennis Series - Barcelona | 2021/11/25 14:30 | Michiel de Krom v Thomas Laurent | 3-6,3-5 |
| UTR Pro Tennis Series - Barcelona | 2021/11/25 08:00 | Michiel de Krom v Euan Mcintosh | 6-0,6-4 |
| UTR Pro Tennis Series - Barcelona | 2021/11/22 09:30 | Michiel de Krom v Sergio Redondo | 6-3,5-3 |
| 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 |
| UTR Pro Tennis Series - Amsterdam | 2021/11/07 10:30 | Guy Den Heijer v Sem Verbeek | 6-3,6-3 |
| UTR Pro Tennis Series - Amsterdam | 2021/11/06 12:00 | Deney Wassermann v Guy Den Heijer | 2-6,5-6 |