Stadium: Ochsenhausen, Germany
| Challenger Series TT | 2023/06/22 12:30 | Dennis Klein v Johannes Willeke | L | 3-0 |
| Challenger Series TT | 2023/06/19 06:30 | Dennis Klein v Johannes Willeke | L | 3-0 |
| Challenger Series TT | 2023/07/06 09:10 | Johannes Willeke v Hannes Hormann | L | 2-3 |
| Challenger Series TT | 2023/07/06 06:30 | Johannes Willeke v Liang Qiu | W | 3-2 |
| Challenger Series TT | 2023/06/23 08:30 | Samuel Amann v Johannes Willeke | W | 0-3 |
| Challenger Series TT | 2023/06/23 07:10 | Carlo Rossi v Johannes Willeke | L | 3-0 |
| Challenger Series TT | 2023/06/22 17:10 | Sven Happek v Johannes Willeke | W | 2-3 |
| Challenger Series TT | 2023/06/22 15:10 | Ihor Zavadskyi v Johannes Willeke | L | 3-1 |
| Challenger Series TT | 2023/06/22 12:30 | Dennis Klein v Johannes Willeke | L | 3-0 |
| Challenger Series TT | 2023/06/22 11:10 | Dauud Cheaib v Johannes Willeke | L | 3-0 |
| Challenger Series TT | 2023/07/06 09:50 | Dennis Klein v David Reitspies | W | 3-0 |
| Challenger Series TT | 2023/07/06 07:50 | Dennis Klein v Dauud Cheaib | W | 3-1 |
| Challenger Series TT | 2023/07/04 13:30 | Dennis Klein v Benjamin Fruchart | W | 3-2 |
| Challenger Series TT | 2023/07/04 11:25 | Kirill Fadeev v Dennis Klein | W | 2-3 |
| Challenger Series TT | 2023/07/04 09:10 | Dennis Klein v Mathias Golab | W | 3-0 |
| Challenger Series TT | 2023/07/03 19:50 | Dennis Klein v Benjamin Fruchart | L | 0-3 |
| Challenger Series TT | 2023/07/03 17:10 | Dennis Klein v Daniel Rinderer | W | 3-1 |
| Challenger Series TT | 2023/07/03 14:30 | Tobias Slanina v Dennis Klein | W | 1-3 |