Stadium: Court 9 Round: 25 Ground: Clay
| ITF M15 Vejle | 2021/07/28 12:50 | Christian Sigsgaard v Ryan Nijboer | 6-3,6-2 |
| Challenger Amersfoort | 2021/07/13 10:15 | Ryan Nijboer v Johan Nikles | 6-7,2-6 |
| ITF M25 Marburg | 2021/07/10 11:00 | Ryan Nijboer v Nick Hardt | 2-6,4-6 |
| ITF M25 Marburg | 2021/07/09 12:00 | Ryan Nijboer v Milan Welte | 4-6,6-3,6-1 |
| ITF M25 Marburg | 2021/07/08 09:00 | Ryan Nijboer v Tim Handel | 6-3,6-4 |
| 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 Frederiksberg | 2021/08/02 11:05 | Nazim Makhlouf v Leyton Rivera | 3-6,6-3,3-10 |
| ITF M15 Frederiksberg | 2021/08/01 10:00 | Eirik Groener v Leyton Rivera | 2-6,5-7 |
| ITF M15 Poprad | 2021/07/05 08:00 | Dominik Palan v Leyton Rivera | 6-3,6-2 |
| ITF M15 Poprad | 2021/07/04 11:00 | Samo Polakovic v Leyton Rivera | 4-6,6-0,4-10 |
| ITF M15 Skopje | 2021/06/07 13:00 | Toby Martin v Leyton Rivera | 7-6,5-7,11-9 |
| ITF M15 Novomoskovsk | 2021/05/31 10:00 | Leyton Rivera v Dzianis Zharyn | 6-7,2-6 |
| ITF M15 Novomoskovsk | 2021/05/31 06:15 | Leyton Rivera v Illya Maksymchuk | 6-1,6-3 |
| ITF M15 Novomoskovsk | 2021/05/30 06:15 | Manfred Fellin v Leyton Rivera | 4-6,6-3,6-10 |