| Lithuanian Int. | 2021/06/12 14:20 | B.R. Sankeerth v Kai Niederhuber | L | 2-0 |
| Lithuanian Int. | 2021/06/12 08:00 | Kai Niederhuber v Shaun Ekengren | W | 2-1 |
| Lithuanian Int. | 2021/06/11 09:45 | Samuel Cassar v Kai Niederhuber | W | 1-2 |
| Lithuanian Int. Qual | 2021/06/10 16:00 | Kai Niederhuber v Kilian Ming-Zhe Maurer | W | 2-0 |
| Austrian Open - Qualif. | 2021/05/27 15:10 | Kai Niederhuber v Klindt, Philip Illum | L | 1-2 |
| Austrian Open - Qualif. | 2021/05/27 10:35 | Sudarma, Lenny v Kai Niederhuber | W | 0-2 |
| Slovenia Int. Qual | 2021/05/19 14:00 | Amaury Lievre v Kai Niederhuber | L | 2-0 |
| Austrian Open - Qualif. | 2020/02/19 11:55 | Kai Niederhuber v Karpov, Georgii | L | 1-2 |
| Polish Int. Qual | 2021/09/23 10:00 | Pratama, Adi v Finn Achthoven | L | 2-0 |
| Spain Int Qual | 2021/06/16 15:25 | Elias Bracke v Finn Achthoven | L | 2-0 |
| Spain Int Qual | 2021/06/16 09:40 | Joseph Waugh v Finn Achthoven | W | 0-2 |
| Austrian Open - Qualif. | 2021/05/27 09:50 | Finn Achthoven v Ivancic, Miha | L | 1-2 |
| Slovenia Int. | 2021/05/20 11:20 | Finn Achthoven v Alex Lanier | L | 0-2 |
| Portuguese Int. Qual | 2021/05/06 14:00 | Robin Mesman v Finn Achthoven | L | 2-1 |
| Championnats d'Europe par équipe | 2020/02/14 15:00 | Finn Achthoven v Harry Huang | L | 0-2 |
| Championnats d'Europe par équipe | 2020/02/12 12:30 | Finn Achthoven v Jerome Pauquet | W | 2-0 |