| Challenger Series TT | 2023/01/09 14:10 | Sven Happek v Dennis Klein | L | 0-3 |
| Challenger Series TT | 2022/07/12 08:30 | Sven Happek v Dennis Klein | L | 1-3 |
| Challenger Ochsenhausen | 2022/06/23 06:30 | Dennis Klein v Sven Happek | L | 3-0 |
| Challenger Ochsenhausen | 2022/06/20 15:10 | Dennis Klein v Sven Happek | L | 3-1 |
| Challenger Ochsenhausen | 2022/05/12 12:30 | Dennis Klein v Sven Happek | L | 3-0 |
| Challenger Ochsenhausen | 2021/12/13 21:00 | Dennis Klein v Sven Happek | L | 3-0 |
| Challenger Ochsenhausen | 2021/12/01 12:50 | Sven Happek v Dennis Klein | L | 0-3 |
| Challenger Ochsenhausen | 2021/07/14 06:30 | Sven Happek v Dennis Klein | W | 3-2 |
| Challenger Ochsenhausen | 2021/02/24 12:50 | Sven Happek v Dennis Klein | L | 0-3 |
| Challenger Ochsenhausen | 2021/01/29 10:50 | Sven Happek v Dennis Klein | L | 0-3 |