Stadium: Herbie Court Round: 26 Ground: Clay
| ITF M25 Marburg | 2021/07/07 09:00 | Yan Sabanin v Ryan Nijboer | 0-6,3-6 |
| ITF M25 The Hague | 2021/06/30 12:55 | Mateus Alves v Ryan Nijboer | 7-6,6-3 |
| ITF M25 Alkmaar | 2021/06/24 12:00 | Marko Tepavac v Ryan Nijboer | 4-6,7-6,6-1 |
| 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 M25 Marburg | 2021/07/07 09:00 | Tim Handel v Dominik Recek | 2-6,6-4,6-4 |
| ITF M25 Marburg | 2021/07/06 14:40 | Aleksandre Bakshi v Tim Handel | 3-6,2-6 |
| ITF M25 Marburg | 2021/07/05 14:10 | Deney Wassermann v Tim Handel | 6-7,6-7 |
| ITF M25 Klosters | 2021/06/24 11:15 | Jakub Paul v Tim Handel | 6-3,6-3 |
| ITF M25 Klosters | 2021/06/23 10:30 | Luca Castelnuovo v Tim Handel | 6-7,2-6 |
| ITF M25 Klosters | 2021/06/21 08:35 | Louroi Martinez v Tim Handel | 7-5,6-7,11-9 |
| ITF M25 Klosters | 2021/06/20 10:10 | Adrien Burdet v Tim Handel | 2-6,5-7 |
| ITF M15 Antalya | 2021/05/26 09:05 | Matteo Gigante v Tim Handel | 6-2,6-4 |