Stadium: Court 2 Round: 27 Ground: Clay
| ITF M15 - Frankfurt Am Main | 2023/08/10 09:00 | Lucas Gerch v Facundo Yunis | 6-1,6-2 |
| ITF M15 - Frankfurt Am Main | 2023/08/09 10:15 | Lucas Gerch v Niels Visker | 6-0,6-1 |
| Challenger - Troyes | 2023/07/06 11:00 | Lucas Gerch v Lorenzo Giustino | 3-6,6-3,3-6 |
| Challenger - Troyes | 2023/07/04 15:05 | Lucas Gerch v Elmar Ejupovic | 6-3,6-2 |
| Challenger - Modena | 2023/06/27 19:40 | Lucas Gerch v Rodrigo Pacheco Mendez | 6-7,4-6 |
| Challenger - Modena | 2023/06/26 08:00 | Timo Stodder v Lucas Gerch | 4-6,2-6 |
| Challenger - Modena | 2023/06/25 08:00 | Gabriele Bosio v Lucas Gerch | 4-6,4-6 |
| Challenger - Parma | 2023/06/18 14:00 | Lucas Gerch v Filippo Moroni | 6-1,1-6,4-6 |
| ITF M15 - Frankfurt Am Main | 2023/08/10 10:55 | Kai Lemstra v Johannes Haerteis | 7-5,4-6,2-6 |
| Challenger - Porto | 2023/08/01 16:10 | Johannes Haerteis v Emilio Nava | 6-7,6-7 |
| Challenger - Porto | 2023/07/31 10:00 | Hugo Maia v Johannes Haerteis | 5-7,5-7 |
| Challenger - Porto | 2023/07/30 10:00 | Johannes Haerteis v Victor Lilov | 6-4,2-6,6-2 |
| ITF M25 - Porto | 2023/07/27 11:45 | Johannes Haerteis v Joao Domingues | 6-2,6-7,2-6 |
| ITF M25 - Porto | 2023/07/26 11:35 | Tomas Pinho v Johannes Haerteis | 4-6,6-7 |
| ITF M15 - Cluj Napoca | 2023/06/22 06:50 | Johannes Haerteis v Gabi Adrian Boitan | 2-6,3-6 |
| ITF M15 - Cluj Napoca | 2023/06/21 09:10 | Dan Alexandru Tomescu v Johannes Haerteis | 4-6,2-6 |