Stadium: Center Court Round: 25 Ground: Clay
| 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 |
| ITF M15 Monastir | 2021/03/10 10:30 | Yannick Mertens v Constantin Schmitz | 6-0,6-2 |
| ITF M25 Wetzlar | 2021/08/03 08:55 | Johann Lars v Jannik Rother | 6-4,5-7,5-10 |
| ITF M25 Wetzlar | 2021/08/02 12:45 | Jannik Rother v Gilad Tamar | 6-1,6-0 |
| ITF M15 Troisdorf | 2021/05/09 10:00 | Aliaksandr Bulitski v Jannik Rother | 6-4,1-6,10-7 |
| ITF M25 Meerbusch | 2021/04/11 13:30 | Jannik Rother v Milan Welte | 2-6,2-6 |
| ITF M15 Oldenzaal | 2019/08/14 17:20 | Jannik Rother v Guy Den Heijer | 7-5,3-6,4-6 |
| ITF M15 Oldenzaal | 2019/08/13 07:30 | Dax Donders v Jannik Rother | 5-7,0-6 |
| ITF M15 Oldenzaal | 2019/08/12 07:30 | Lars Bijsterbosch v Jannik Rother | 0-6,2-6 |
| ITF M25 Kassel | 2019/07/15 11:00 | Jannik Rother v Timo Stodder | 4-6,5-7 |