| Challenger Series TT | 08/04 08:30 | - | Hannes Hormann v Karl Zimmermann | L | 3-1 | |
| Challenger Series TT | 08/04 07:10 | - | Bohdan Sinkevych v Karl Zimmermann | L | 3-1 | |
| Challenger Series TT | 08/03 17:10 | - | Marco Stefanidis v Karl Zimmermann | W | 2-3 | |
| Challenger Series TT | 08/03 15:10 | - | Zeng Yi Wang v Karl Zimmermann | L | 3-1 | |
| Challenger Series TT | 08/03 12:30 | - | Daniel Rinderer v Karl Zimmermann | L | 3-1 | |
| Challenger Series TT | 08/03 11:10 | - | Anton Limonov v Karl Zimmermann | L | 3-0 | |
| Challenger Series TT | 08/03 06:30 | - | Damian Zech v Karl Zimmermann | W | 1-3 | |
| Challenger Series TT | 05/30 09:10 | - | Simon Berglund v Karl Zimmermann | L | 3-0 | |
| Challenger Series TT | 05/30 06:30 | - | Anton Limonov v Karl Zimmermann | L | 3-0 | |
| Challenger Series TT | 05/29 17:10 | - | Karl Zimmermann v Ryoichi Yoshiyama | L | 2-3 | |
| Challenger Series TT | 05/29 15:10 | - | Karl Zimmermann v Bohdan Sinkevych | - | CANC | |
| Challenger Series TT | 05/29 13:10 | - | Peter Hribar v Karl Zimmermann | L | 3-0 |