Stadium: Court 8 Round: 54 Ground: Clay
| ITF M25 - Haag | 2021/06/27 08:00 | Guy Den Heijer v Jing L Weng | 6-3,6-4 |
| ITF M25 - Alkmaar | 2021/06/23 09:00 | Kaichi Uchida v Guy Den Heijer | 7-6,6-3 |
| ITF M25 - Alkmaar | 2021/06/21 18:00 | Vladimir Ivanov v Guy Den Heijer | 3-6,6-7 |
| ITF M25 - Alkmaar | 2021/06/20 17:00 | Alec Deckers v Guy Den Heijer | 3-6,7-6,4-10 |
| ITF M25 - Vic | 2021/05/16 08:00 | Mateus Alves v Guy Den Heijer | 6-2,6-3 |
| ITF M15 - Valldoreix | 2021/05/09 13:00 | Guy Den Heijer v Pol Amoros Ramos | 3-6,2-6 |
| ITF M15 - Majadahonda | 2021/05/02 16:15 | Taiyo Yamanaka v Guy Den Heijer | 6-7,6-3,11-9 |
| ITF M15 - Antalya | 2021/03/25 07:00 | Guy Den Heijer v Juan Pablo Paz | 1-6,2-6 |
| ITF M25 - Haag | 2021/06/27 08:00 | Max Van Nunen v Jack Gibbens | 6-2,3-6,16-14 |
| ITF M15 - Alkmaar | 2020/08/23 08:00 | Max Van Nunen v Simon Beaupain | 5-7,5-7 |
| ITF M15 - Koksijde | 2019/08/13 10:40 | Lautaro Agustin Falabella v Max Van Nunen | 6-3,6-0 |
| ITF M15 - Koksijde | 2019/08/12 14:40 | Max Van Nunen v Ivan Denisov | 3-6,7-5,12-10 |
| ITF Belgium F12 Qual | 2017/09/02 11:00 | Boris Beumer v Max Van Nunen | 6-4,4-6,6-1 |
| ITF Netherlands F2 Qual | 2017/06/24 09:00 | Nick Broekhof v Max Van Nunen | 6-1,6-4 |