Stadium: Court 6 Round: 54 Ground: Clay
| ITF M15 - Heraklion | 2021/06/08 08:00 | Eduardo Cohen v Alec Deckers | 3-6,7-6,10-7 |
| ITF M15 - Heraklion | 2021/06/07 07:30 | Alec Deckers v Toby D. Boyer | 7-6,6-1 |
| ITF M15 - Heraklion | 2021/06/02 08:20 | Petros Tsitsipas v Alec Deckers | 6-4,6-4 |
| ITF M15 - Heraklion | 2021/05/26 08:35 | Daniel Cox v Alec Deckers | 6-1,6-0 |
| ITF M15 - Heraklion | 2020/11/15 08:00 | Guy Dagan v Alec Deckers | 0-6,1-6 |
| ITF M15 - Heraklion | 2020/11/01 10:00 | Alec Deckers v Riccardo Balzerani | 4-6,2-6 |
| ITF M15 - Heraklion | 2020/10/25 11:30 | Alec Deckers v Francesco Maestrelli | 7-6,0-6,3-10 |
| ITF M15 - Caslano | 2020/09/01 12:10 | Alec Deckers v Federico Iannaccone | 2-6,7-5,4-10 |
| 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 M15 - Antalya | 2021/03/24 06:30 | Guy Den Heijer v Carlo Alberto Fossati | 6-2,6-3 |
| ITF M15 - Antalya | 2021/03/22 07:00 | Guy Den Heijer v Vladislav Gorbatenko | 7-5,6-0 |
| ITF M15 - Antalya | 2021/03/21 07:00 | Guy Den Heijer v Alexander Ovcharov | 6-1,6-2 |
| ITF M15 - Antalya | 2021/03/17 08:00 | Koray Kirci v Guy Den Heijer | 6-4,6-2 |