Stadium: Court 1 Round: 25 Ground: Hardcourt indoor
| Challenger Rennes | 2021/09/14 16:45 | Tobias Kamke v Arthur Rinderknech | 3-6,6-3,3-6 |
| Challenger Mallorca | 2021/09/04 14:00 | Lukas Lacko v Tobias Kamke | 6-0,6-3 |
| Challenger Mallorca | 2021/09/03 16:00 | Tobias Kamke v Fernando Verdasco | 6-3,6-1 |
| Challenger Mallorca | 2021/09/02 14:30 | Tobias Kamke v Nick Chappell | 6-2,6-4 |
| Challenger Mallorca | 2021/09/01 16:00 | Blaz Rola v Tobias Kamke | 4-6,4-6 |
| US Open | 2021/08/24 17:05 | Tobias Kamke v Illya Marchenko | 6-3,6-7,2-6 |
| Challenger Meerbusch | 2021/08/09 14:00 | Lukas Klein v Tobias Kamke | 6-1,6-2 |
| Challenger Poznan | 2021/07/27 08:00 | Mats Moraing v Tobias Kamke | 6-4,6-2 |
| Challenger Banja Luka | 2021/09/08 10:50 | Dimitar Kuzmanov v Zdenek Kolar | 5-7,2-6 |
| Challenger Banja Luka | 2021/09/06 14:10 | Dimitar Kuzmanov v Alexander Shevchenko | 3-6,6-4,6-1 |
| Challenger Mallorca | 2021/09/02 17:00 | Dimitar Kuzmanov v Lukas Lacko | 2-6,6-7 |
| Challenger Mallorca | 2021/09/01 17:50 | Kacper Zuk v Dimitar Kuzmanov | 3-6,4-6 |
| US Open | 2021/08/24 22:45 | Dimitar Kuzmanov v Marius Copil | 6-7,4-6 |
| Challenger Tampere | 2021/07/21 09:00 | Dimitar Kuzmanov v Kyrian Jacquet | 6-3,4-6,6-7 |
| Challenger Tampere | 2021/07/19 15:30 | Kimmer Coppejans v Dimitar Kuzmanov | 6-1,3-6,6-7 |
| Challenger Iasi | 2021/07/16 09:40 | Felipe Meligeni Rodrigues Alves v Dimitar Kuzmanov | 6-0,3-6,6-3 |