| Challenger Series TT | 9-11,11-9,11-3,3-11 | 2 | Albert Vilardell vs Dennis Klein | - | 8-10 |
| Challenger Series TT | 04/26 09:25 | - | Bohdan Sinkevych v Dennis Klein | W | 0-3 | |
| Challenger Series TT | 04/26 08:15 | - | Dennis Klein v Albert Vilardell | W | 3-1 | |
| Challenger Series TT | 04/25 17:50 | - | Mike Hollo v Dennis Klein | L | 3-1 | |
| Challenger Series TT | 04/25 15:30 | - | Benjamin Fruchart v Dennis Klein | L | 3-0 | |
| Challenger Series TT | 04/25 13:45 | - | Dauud Cheaib v Dennis Klein | W | 2-3 | |
| Challenger Series TT | 04/25 09:25 | - | Damian Zech v Dennis Klein | W | 0-3 | |
| Challenger Series TT | 04/25 07:05 | - | Kirill Fadeev v Dennis Klein | W | 0-3 | |
| Challenger Series TT | 04/12 08:15 | - | Dennis Klein v Daniel Rinderer | - | CANC | |
| Challenger Series TT | 02/27 14:30 | 1 | Liang Qiu v Dennis Klein | W | 1-3 | |
| Challenger Series TT | 02/27 13:05 | 2 | Dennis Klein v Mohammed Javad Sohrabi | W | 3-0 | |
| Challenger Series TT | 02/27 08:50 | - | Alexander Valuch v Dennis Klein | W | 1-3 | |
| Challenger Series TT | 02/26 20:50 | - | Samuel Amann v Dennis Klein | W | 0-3 |