Stadium: CEE Logistic Round: 28 Ground: Clay
| ITF - M15 Trier | 2023/08/22 11:00 | Kai Lemstra v Adrian Oetzbach | 7-6,6-3 |
| ITF M15 - Allershausen | 2023/09/01 10:00 | Jannik Maute v Adrian Oetzbach | 2-6,3-6 |
| ITF M15 - Allershausen | 2023/08/31 09:55 | Justin Engel v Adrian Oetzbach | 7-6,4-6,4-6 |
| ITF M15 - Allershausen | 2023/08/30 11:05 | Julian Peter v Adrian Oetzbach | 1-6,1-6 |
| ITF - M15 Trier | 2023/08/22 11:00 | Kai Lemstra v Adrian Oetzbach | 7-6,6-3 |
| ITF M15 - Überlingen | 2023/08/18 11:30 | Arthur Nagel v Adrian Oetzbach | 6-1,6-4 |
| ITF M15 - Überlingen | 2023/08/17 13:40 | Adrian Oetzbach v Luca Wiedenmann | 6-2,7-5 |
| ITF M15 - Überlingen | 2023/08/16 09:40 | Philip Florig v Adrian Oetzbach | 2-6,7-5,5-7 |
| Challenger - Meerbusch | 2023/08/06 15:45 | Tibo Colson v Adrian Oetzbach | 7-6,7-6 |
| ITF M15 - Allershausen | 2023/09/01 15:25 | Kai Lemstra v Daniel De Jonge | 7-5,6-1 |
| ITF M15 - Allershausen | 2023/08/31 12:15 | Kai Lemstra v Taym Alazmeh | 6-2,6-2 |
| ITF M15 - Allershausen | 2023/08/30 10:00 | Luca Wiedenmann v Kai Lemstra | 3-6,1-6 |
| ITF - M15 Trier | 2023/08/24 10:30 | Max Wiskandt v Kai Lemstra | 6-4,6-4 |
| ITF - M15 Trier | 2023/08/22 11:00 | Kai Lemstra v Adrian Oetzbach | 7-6,6-3 |
| ITF - M15 Frankfurt Am Main | 2023/08/10 10:55 | Kai Lemstra v Johannes Haerteis | 7-5,4-6,2-6 |
| ITF - M15 Frankfurt Am Main | 2023/08/08 09:00 | Kai Lemstra v Matthew William Donald | 6-3,6-1 |
| ITF - M15 Metzingen | 2023/07/28 10:50 | Kai Lemstra v Sander Jong | 6-3,0-6,2-6 |