Stadium: Court 6 Round: 25 Ground: Clay
| ITF M25 Alkmaar | 2021/06/21 14:25 | Guillaume Dermiens v Zachary Eisinga | 4-6,7-5,13-11 |
| ITF M25 Alkmaar | 2021/06/20 10:30 | Takanyi Garanganga v Guillaume Dermiens | 3-6,1-6 |
| ITF M15 - Antalya | 2021/06/08 07:00 | Franco Roncadelli v Guillaume Dermiens | 6-2,6-0 |
| ITF M15 - Antalya | 2021/06/07 09:35 | Credit Chaiyarin v Guillaume Dermiens | 0-6,4-6 |
| ITF M15 - Antalya | 2021/05/31 08:30 | Nicolas Parizzia v Guillaume Dermiens | 6-3,1-6,10-5 |
| ITF M15 Monastir | 2021/04/11 11:00 | Guillaume Dermiens v Arthur Bouquier | 6-4,5-7,10-12 |
| ITF M15 Monastir | 2021/04/05 09:00 | Hazem Naw v Guillaume Dermiens | 6-2,6-2 |
| ITF M15 Monastir | 2021/04/04 10:30 | Guillaume Dermiens v Samuel Puskar | 6-2,6-3 |
| ITF M15 Skopje | 2021/06/10 11:30 | Miljan Zekic v Ryan Nijboer | 6-2,6-3 |
| ITF M15 Skopje | 2021/06/10 07:45 | Ryan Nijboer v Dian Nedev | 6-3,6-2 |
| ITF M15 Skopje | 2021/06/06 07:55 | Alexis Gautier v Ryan Nijboer | 6-2,3-6,6-2 |
| ITF M15 Skopje | 2021/06/05 10:40 | Dalibor Svrcina v Ryan Nijboer | 6-1,4-6,5-7 |
| ITF M15 Skopje | 2021/06/04 10:25 | Alexander Weis v Ryan Nijboer | 6-7,6-7 |
| ITF M15 Skopje | 2021/06/03 09:30 | Ryan Nijboer v Alex Rybakov | 2-6,7-6,6-4 |
| ITF M15 Skopje | 2021/06/02 09:55 | Niels Visker v Ryan Nijboer | 6-4,3-6,4-6 |
| ITF M25 Vic | 2021/05/19 09:00 | Ryan Nijboer v Facundo Juarez | 6-3,4-6,4-6 |