| Slovenia - Future Series | 2023/09/08 08:45 | Jeppe Bruun Christensen v Kai Niederhuber | L | 2-1 |
| Internazionali di Bonn - Qual. | 2023/05/31 09:10 | Kai Niederhuber v David K Kristensen | L | 0-2 |
| Open d'Austria - Qual. | 2023/05/25 09:55 | Kai Niederhuber v Jia Jie Tan | L | 0-2 |
| Slovenia Open - Qual. | 2023/05/17 16:45 | Kai Niederhuber v Yaro Van Delsen | L | 1-2 |
| Slovenia Open - Qual. | 2023/05/17 09:10 | Kai Niederhuber v Adarsh Palani Kumar | W | 2-0 |
| Open di Lussemburgo - Qual. | 2023/05/04 12:50 | Kai Niederhuber v Bruno Carvalho | L | 0-2 |
| Open di Lussemburgo - Qual. | 2023/05/04 10:30 | Ramnish Kumar v Kai Niederhuber | W | 0-2 |
| Open di Polonia - Qual. | 2023/03/22 16:00 | Matthias Kicklitz v Kai Niederhuber | L | 2-0 |