Stadium: Court 3 Round: 25 Ground: Clay
| ITF M15 Brussels | 2019/07/29 10:00 | Guy Den Heijer v Julian kenzlers | 6-1,6-1 |
| ITF M15 Den Haag | 2019/07/05 14:05 | Guy Den Heijer v Geoffrey Blancaneaux | 6-4,1-6,4-6 |
| ITF M15 Den Haag | 2019/07/04 07:30 | Alex Martinez v Guy Den Heijer | 2-6,2-6 |
| ITF M15 Den Haag | 2019/07/02 12:55 | Guy Den Heijer v Joao Lucas Reis da Silva | 6-4,6-1 |
| ITF M15 Alkmaar | 2019/06/27 10:00 | Matias Zukas v Guy Den Heijer | 6-2,6-1 |
| ITF M15 Alkmaar | 2019/06/26 11:25 | Bart Van Den Berg v Guy Den Heijer | 2-6,7-5,2-6 |
| ITF M15 Alkmaar | 2019/06/25 09:00 | Vasile Antonescu v Guy Den Heijer | 4-6,4-6 |
| ITF M15 Doha | 2019/03/13 12:00 | Jesper De Jong v Guy Den Heijer | 7-5,6-4 |
| ITF M25 Lasne | 2019/07/03 08:00 | Dragos Dima v Guillaume Dermiens | 6-4,6-4 |
| ITF M25 Lasne | 2019/07/02 11:50 | Guillaume Dermiens v Buvaysar Gadamauri | 2-6,6-3,11-9 |
| ITF M25 Lasne | 2019/07/01 15:55 | Dominik Recek v Guillaume Dermiens | 6-4,4-6,7-10 |
| ITF M25 Arlon | 2019/06/25 11:40 | Filip Bergevi v Guillaume Dermiens | 6-3,6-3 |
| ITF M25 Arlon | 2019/06/24 15:15 | Guillaume Dermiens v Arvid Nordquist | 6-1,6-4 |
| ITF M15 Kalmar | 2019/05/14 08:15 | Simon Freund v Guillaume Dermiens | 6-3,4-6,10-6 |
| ITF M15 Kalmar | 2019/05/13 08:15 | Olof Wiklund v Guillaume Dermiens | 6-3,5-7,2-10 |
| ITF Czech Republic F11 Qual | 2018/11/19 11:00 | Ondrej Krstev v Guillaume Dermiens | 6-2,6-2 |