Stadium: Centre Court Round: 14 Ground: Clay
| Challenger Meerbusch | 2021/08/08 08:00 | Bogdan Bobrov v Viktor Durasovic | 2-6,6-7 |
| Challenger Poznan | 2021/07/25 09:00 | Bogdan Bobrov v Miljan Zekic | 4-6,1-6 |
| Challenger Tampere | 2021/07/20 15:35 | Bogdan Bobrov v Pedro Cachin | 1-6,5-7 |
| Challenger Tampere | 2021/07/19 12:25 | Alexander Erler v Bogdan Bobrov | 6-4,5-7,1-6 |
| Challenger Tampere | 2021/07/18 08:00 | Bogdan Bobrov v Markus Eriksson | 7-6,6-4 |
| Challenger Iasi | 2021/07/13 14:05 | Mohamed Aziz Dougaz v Bogdan Bobrov | 6-4,7-6 |
| Challenger Iasi | 2021/07/12 08:00 | Bogdan Bobrov v Dan Alexandru Tomescu | 2-6,3-6 |
| Challenger Iasi | 2021/07/11 08:50 | Bogdan Bobrov v Oleg Prihodko | 6-4,7-6 |
| Challenger Meerbusch | 2021/08/08 16:05 | Ivan Nedelko v Johannes Haerteis | 7-6,6-3 |
| Challenger Segovia | 2021/07/27 13:05 | Altug Celikbilek v Johannes Haerteis | 6-3,6-4 |
| Challenger Pozoblanco | 2021/07/20 20:10 | Cem Ilkel v Johannes Haerteis | 6-2,7-6 |
| Challenger Amersfoort | 2021/07/13 08:30 | Mats Moraing v Johannes Haerteis | 6-1,6-0 |
| Challenger Braunschweig | 2021/07/04 11:55 | Johannes Haerteis v Nino Ehrenschneider | 6-3,3-6,4-6 |
| Challenger Prostejov | 2021/06/15 08:30 | Johannes Haerteis v Federico Coria | 1-6,0-6 |
| Challenger Prostejov | 2021/06/14 08:30 | Johannes Haerteis v David Poljak | 5-7,3-6 |
| Challenger Prostejov | 2021/06/13 09:00 | Johannes Haerteis v Jakub Nicod | 6-3,3-6,6-3 |