Stadium: Ochsenhausen, Germany
| Challenger Series TT | 2023/03/09 15:30 | Karl Zimmermann v Damian Zech | L | 3-0 |
| Challenger Series TT | 2023/07/28 08:30 | Antonin Gavlas v Damian Zech | L | 3-0 |
| Challenger Series TT | 2023/07/28 07:10 | Yoan Rebetez v Damian Zech | L | 3-0 |
| Challenger Series TT | 2023/07/27 14:30 | Guillaume Alcayde v Damian Zech | L | 3-0 |
| Challenger Series TT | 2023/07/27 12:30 | Daniel Rinderer v Damian Zech | L | 3-0 |
| Challenger Series TT | 2023/07/27 11:10 | Dauud Cheaib v Damian Zech | L | 3-0 |
| Challenger Series TT | 2023/07/27 06:30 | Marius Henninger v Damian Zech | L | 3-2 |
| Challenger Series TT | 2023/07/21 10:30 | Damian Zech v Yannick Vostes | L | 0-3 |
| Challenger Series TT | 2023/07/21 07:50 | Damian Zech v Antonin Gavlas | L | 0-3 |
| 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 |
| Challenger Series TT | 2023/05/29 10:30 | Dauud Cheaib v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/05/29 07:50 | Carlo Rossi v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/03/10 11:30 | Karl Zimmermann v Dillon Chambers | L | 1-3 |
| Challenger Series TT | 2023/03/10 08:50 | Karl Zimmermann v Guilherme Teodoro | L | 1-3 |