Stadium: Center Court Round: 19 Ground: Carpet indoor
| Challenger Eckental | 2021/10/31 11:30 | Mischa Zverev v Alen Mujakic | 6-2,6-1 |
| Challenger Ismaning | 2021/10/25 11:25 | Mischa Zverev v Julian Lenz | 5-7,6-7 |
| Challenger Alicante | 2021/10/14 09:30 | Mischa Zverev v Frederico Ferreira Silva | 2-6,0-6 |
| Challenger Alicante | 2021/10/11 14:30 | Vladyslav Orlov v Mischa Zverev | 2-6,1-6 |
| Challenger Mouilleron le Captif | 2021/10/03 11:00 | Mischa Zverev v Jurgen Briand | 3-6,3-6 |
| Challenger Orleans | 2021/09/26 12:05 | Mischa Zverev v Kyrian Jacquet | 6-7,1-6 |
| Challenger Luedenscheid | 2021/08/17 14:45 | Mischa Zverev v Julien Cagnina | 3-6,1-6 |
| Challenger Prag | 2021/08/09 15:30 | Riccardo Bonadio v Mischa Zverev | 6-3,2-6,6-3 |
| Challenger Eckental | 2021/10/31 10:00 | Aldin Setkic v Christopher Heyman | 4-6,5-7 |
| ITF M25 - Nevers | 2021/10/06 13:00 | Christopher Heyman v Luca Van Assche | 4-6,6-7 |
| Challenger Lissabon | 2021/09/26 10:45 | Christopher Heyman v Lucas Gerch | 4-6,7-6,5-7 |
| Challenger Biel | 2021/09/19 09:30 | Jakub Paul v Christopher Heyman | 7-6,4-6,7-5 |
| Challenger Istanbul | 2021/09/16 08:00 | Yasutaka Uchiyama v Christopher Heyman | 3-6,6-3,6-4 |
| Challenger Istanbul | 2021/09/14 08:40 | Christopher Heyman v Andrea Arnaboldi | 3-6,6-2,6-4 |
| Challenger Istanbul | 2021/09/13 07:30 | Geoffrey Blancaneaux v Christopher Heyman | 4-6,4-6 |
| Challenger Istanbul | 2021/09/12 08:00 | Artem Dubrivnyy v Christopher Heyman | 3-6,2-6 |