Stadium: Court 7 Round: 62 Ground: Hardcourt outdoor
| ITF - M15 Monastir | 2021/11/15 08:00 | Dermiens, Guillaume v Martinez Irigoyen, Astur | 6-2,6-4 |
| ITF - M15 Monastir | 2021/11/10 12:00 | Gauthier Onclin v Dermiens, Guillaume | 6-1,6-1 |
| ITF - M15 Monastir | 2021/11/08 08:00 | Dermiens, Guillaume v Alessandro Coccioli | 6-4,6-2 |
| ITF M25 Eupen | 2021/09/07 09:30 | Dermiens, Guillaume v Cloes, Loic | 3-6,0-6 |
| ITF M25 Eupen | 2021/09/06 07:30 | Dermiens, Guillaume v Adan Freire Da Silva | 7-6,6-1 |
| ITF M25 Eupen | 2021/09/05 09:00 | Dermiens, Guillaume v Panagoulopoulos, Gosse | 6-2,6-2 |
| ITF M15 Huy | 2021/08/24 09:20 | Dermiens, Guillaume v Sollie, Thorsten | 4-6,3-6 |
| ITF M15 Huy | 2021/08/23 11:35 | Dermiens, Guillaume v Tzicas, Charles | 6-3,6-0 |
| ITF - M15 Monastir | 2021/11/15 08:00 | Thibaut Gadilhe v Jans, Jarno | 2-6,0-6 |
| ITF - M15 Monastir | 2021/11/11 07:55 | Simon Beaupain v Jans, Jarno | 6-4,6-2 |
| ITF - M15 Monastir | 2021/11/10 10:45 | Jans, Jarno v Robin Bertrand | 6-3,7-5 |
| ITF - M15 Monastir | 2021/11/08 09:00 | Elgin Khoeblal v Jans, Jarno | 4-6,7-5,4-10 |
| ITF M15 Oldenzaal | 2021/08/16 10:30 | George Loffhagen v Jans, Jarno | 6-2,7-5 |
| ITF M15 Oldenzaal | 2021/08/15 07:30 | Jans, Jarno v Paulo A S Dos Santos | 7-5,6-1 |
| ITF M25 The Hague | 2021/06/27 08:00 | Veldheer, Mick v Jans, Jarno | 6-4,6-1 |