| Slovenia Open Quals | 2024/05/15 14:50 | Christian Tomic v Kai Niederhuber | W | 0-2 |
| Portugal Int. Qual | 2024/03/06 15:40 | Kai Niederhuber v Garret Tan | L | 1-2 |
| Hungarian Int. Qual | 2023/11/01 15:20 | Enrico Baroni v Kai Niederhuber | L | 2-0 |
| Hungarian Int. Qual | 2023/11/01 10:55 | Pavel Manasek v Kai Niederhuber | W | 0-2 |
| Czech Open Qual | 2023/10/19 16:45 | Kim Linell v Kai Niederhuber | L | 2-1 |
| Croatian Int. | 2023/09/29 09:55 | Simon Baron-Vezilier v Kai Niederhuber | L | 2-0 |
| Croatia Int. Qual | 2023/09/28 18:30 | Felix Wright v Kai Niederhuber | W | 0-2 |
| Croatia Int. Qual | 2023/09/28 15:10 | Edvin Hadzihalilovic v Kai Niederhuber | W | 0-2 |
| Slovenia Open Quals | 2024/05/15 15:25 | Lennart Notni v Koushiik C. S | W | 0-2 |