Stadium: Center Court Round: 26 Ground: Clay
| ITF M25 Wetzlar | 2021/08/04 09:55 | Dayne Kelly v Gabriel Alejandro Hidalgo | 6-7,6-2,6-4 |
| Challenger Braunschweig | 2021/07/06 10:30 | Benjamin Hassan v Dayne Kelly | 6-4,7-6 |
| Challenger Braunschweig | 2021/07/05 09:30 | Diego Hidalgo v Dayne Kelly | 3-6,7-6,3-6 |
| ITF M25 The Hague | 2021/07/01 14:05 | Dayne Kelly v Marko Tepavac | 6-7,3-6 |
| ITF M25 The Hague | 2021/06/29 15:00 | Dayne Kelly v Guy Den Heijer | 6-1,6-4 |
| ITF M25 Montauban | 2021/06/24 10:00 | Valentin Royer v Dayne Kelly | 7-6,6-2 |
| ITF M25 Montauban | 2021/06/23 08:25 | Loris Pourroy v Dayne Kelly | 4-6,4-6 |
| Challenger Orlando | 2021/06/08 16:00 | Dayne Kelly v Guido Andreozzi | 6-4,4-6,5-7 |
| ITF M25 Wetzlar | 2021/08/04 12:30 | Constantin Schmitz v Jannik Rother | 6-2,6-0 |
| ITF M15 Troisdorf | 2021/05/12 09:00 | Constantin Schmitz v Tom Kocevar-Desman | 6-4,4-6,3-6 |
| ITF M15 Antalya | 2021/04/14 10:30 | Ivan Sergeyev v Constantin Schmitz | 6-3,5-7,6-3 |
| ITF M15 Antalya | 2021/04/08 06:55 | Flavio Cobolli v Constantin Schmitz | 7-6,7-6 |
| ITF M15 Antalya | 2021/04/06 07:00 | Constantin Schmitz v Bogdan Bobrov | 6-1,6-4 |
| ITF M15 Antalya | 2021/03/30 08:30 | Pol Martin Tiffon v Constantin Schmitz | 6-4,7-6 |
| ITF M15 Antalya | 2021/03/26 07:00 | Georgii Kravchenko v Constantin Schmitz | 6-2,6-3 |
| ITF M15 Antalya | 2021/03/24 07:30 | Constantin Schmitz v Pedro Vives Marcos | 6-3,6-3 |