Stadium: Court 1 Round: 25 Ground: Clay
| Challenger Warsaw | 2021/08/25 10:30 | Johan Nikles v Jozef Kovalik | 3-6,4-6 |
| Challenger Warsaw | 2021/08/24 11:30 | Johan Nikles v Jonathan Mridha | 6-4,6-7,6-3 |
| Challenger Warsaw | 2021/08/22 13:35 | Johan Nikles v Lucas Gerch | 6-4,7-5 |
| ATP Gstaad | 2021/07/19 10:30 | Johan Nikles v Vit Kopriva | 2-6,1-6 |
| Challenger Amersfoort | 2021/07/15 18:05 | Johan Nikles v Lukas Rosol | 2-6,1-6 |
| Challenger Amersfoort | 2021/07/13 10:15 | Ryan Nijboer v Johan Nikles | 6-7,2-6 |
| Challenger Amersfoort | 2021/07/12 09:00 | Jeremy Jahn v Johan Nikles | 2-6,3-6 |
| Challenger Amersfoort | 2021/07/11 14:00 | Dominik Palan v Johan Nikles | 4-6,6-7 |
| UTR Pro Tennis Series Barcelona | 2021/08/15 08:00 | Olexiy Kolisnyk v Federico Zeballos | 2-6,6-2,6-4 |
| UTR Pro Tennis Series Barcelona | 2021/08/14 06:30 | Federico Zeballos v Oleksandr Bielinskyi | 6-0,6-3 |
| UTR Pro Tennis Series Barcelona | 2021/08/13 08:00 | Bruno P Navarro v Federico Zeballos | 1-5 |
| UTR Pro Tennis Series Barcelona | 2021/08/12 08:30 | Luc Fomba v Federico Zeballos | 7-5,5-3 |
| UTR Pro Tennis Series Barcelona | 2021/08/09 11:00 | Marat Deviatiarov v Federico Zeballos | 5-7,1-6 |
| UTR Pro Tennis Series Barcelona | 2021/08/07 08:30 | Kuzey Cekirge v Federico Zeballos | 6-4,4-6,7-5 |
| UTR Pro Tennis Series Barcelona | 2021/08/06 11:30 | Federico Zeballos v Pablo Carretero | 6-0,6-1 |
| UTR Pro Tennis Series Barcelona | 2021/08/04 07:00 | Federico Zeballos v Angel G Melgar | 6-4,6-4 |