Stadion: Court 8 Round: 26 Ground: Clay
| 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 |
| ITF - M25 - Vic | 2021/05/18 08:00 | Laurent Lokoli v Ryan Nijboer | 3-6,4-6 |
| ITF - M25 - Vic | 2021/05/17 08:00 | Pedro Araujo v Ryan Nijboer | 6-3,0-6,4-10 |
| ITF - M25 - Vic | 2021/05/16 07:00 | Allan Deschamps v Ryan Nijboer | 7-6,4-6,4-10 |
| ITF - M15 - Valldoreix | 2021/05/10 09:00 | Francisco Cabral v Ryan Nijboer | 6-1,7-5 |
| ITF - M15 - Valldoreix | 2021/05/09 13:00 | Matvey Minin v Ryan Nijboer | 6-7,2-6 |
| ITF - M15 - Majadahonda | 2021/05/03 10:45 | Emilien Voisin v Ryan Nijboer | 5-7,6-2,10-4 |
| ITF - M15 - Skopje | 2021/06/02 08:00 | Kalin Ivanovski v Alex Rybakov | 2-6,2-6 |
| ITF - M25 - Most | 2021/05/29 08:30 | Dalibor Svrcina v Alex Rybakov | 6-2,6-2 |
| ITF - M25 - Most | 2021/05/28 08:30 | Daniel Michalski v Alex Rybakov | 4-6,4-6 |
| ITF - M25 - Most | 2021/05/27 08:00 | Alex Rybakov v Filip Peliwo | 6-1,6-2 |
| ITF - M25 - Most | 2021/05/26 07:55 | Alex Rybakov v Martin Damm | 6-4,6-2 |
| ITF - M25 - Vic | 2021/05/18 08:00 | Alex Rybakov v Pedro Vives Marcos | 2-6,4-6 |
| ITF - M25 - Vic | 2021/05/17 09:00 | Alex Rybakov v Max Alcala Gurri | 6-2,7-5 |
| ITF - M15 - Valldoreix | 2021/05/11 11:00 | Alex Rybakov v Martin Cuevas | 5-7,3-6 |