Stadium: Ochsenhausen, Germany
| Challenger Series TT | 2023/08/03 14:30 | Daniel Rinderer v Marco Stefanidis | L | 3-1 |
| Challenger Series TT | 2023/08/03 11:50 | Damian Zech v Marco Stefanidis | L | 3-1 |
| Challenger Series TT | 2023/08/03 09:50 | Marco Stefanidis v Hannes Hormann | L | 2-3 |
| Challenger Series TT | 2023/08/03 07:50 | Marco Stefanidis v Zengyi Wang | L | 1-3 |
| Challenger Series TT | 2023/07/21 09:50 | Marco Stefanidis v Amirreza Abbasi | L | 0-3 |
| Challenger Series TT | 2023/07/21 06:30 | Marco Stefanidis v Yannick Vostes | L | 0-3 |
| Challenger Series TT | 2023/07/20 17:50 | Marco Stefanidis v Antonin Gavlas | L | 0-3 |
| Challenger Series TT | 2023/07/20 16:30 | Marco Stefanidis v Miroslav Hořejší | L | 1-3 |
| Challenger Series TT | 2023/08/03 15:10 | Zengyi Wang v Karl Zimmermann | L | 3-1 |
| Challenger Series TT | 2023/08/03 12:30 | Daniel Rinderer v Karl Zimmermann | L | 3-1 |
| Challenger Series TT | 2023/08/03 11:10 | Anton Limonov v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/08/03 06:30 | Damian Zech v Karl Zimmermann | W | 1-3 |
| Challenger Series TT | 2023/05/30 09:10 | Simon Berglund v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/05/30 06:30 | Anton Limonov v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/05/29 17:10 | Karl Zimmermann v Ryoichi Yoshiyama | L | 2-3 |
| Challenger Series TT | 2023/05/29 13:10 | Peter Hribar v Karl Zimmermann | L | 3-0 |