Stadium: Court 8 Round: 27 Ground: Clay
| ITF - M15 Skopje | 2021/06/03 08:00 | Alexander Weis v Martin Damm | 6-3,6-2 |
| ITF - M15 Skopje | 2021/06/01 11:00 | Mats Rosenkranz v Alexander Weis | 4-6,6-2,0-6 |
| ITF - M15 Valldoreix | 2021/05/09 14:00 | Louis Dussin v Alexander Weis | 6-3,6-1 |
| ITF - M15 LPD Gran Canaria | 2021/04/29 11:55 | Alexander Weis v Eduard Esteve Lobato | 3-6,2-6 |
| ITF - M15 LPD Gran Canaria | 2021/04/28 11:25 | Alexander Weis v Diego F Flores | 0-6,6-2,6-3 |
| ITF - M25 Angers | 2021/04/20 10:35 | Alexander Weis v Vincent Stouff | 7-6,3-6,3-6 |
| ITF - M25 Angers | 2021/04/19 10:35 | Alexander Weis v Simon Reveniau | 6-3,6-3 |
| ITF - M25 Reus | 2021/04/12 07:30 | Alexander Weis v Sean Cuenin | 2-6,6-4,10-3 |
| 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 |
| 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 |