| Open de Pologne - Qualif. | 2023/03/22 09:45 | Palakkal, S. v Joel Koenig | L | 2-1 |
| International du Portugal | 2023/03/10 12:05 | Danylo Bosniuk v Joel Koenig | L | 2-0 |
| Welsh Int. Qual | 2022/11/30 09:40 | Heng Lin Ngan v Joel Koenig | L | 2-0 |
| Welsh Int. Qual | 2022/11/29 13:05 | Luke Griffiths v Joel Koenig | W | 0-2 |
| Hungarian Int. | 2022/11/03 13:20 | Harry Huang v Joel Koenig | L | 2-0 |
| Croatia Open | 2022/06/21 14:55 | Joel Koenig v Cholan Kayan | L | 0-2 |
| International de Bonn | 2022/06/16 11:10 | Joel Koenig v Cholan Kayan | L | 0-2 |
| Austrian Open | 2022/05/28 08:40 | Karunaratne, Niluka v Joel Koenig | L | 2-0 |
| Dutch Int. - Qualif. | 2023/04/13 20:00 | Ze Xi Sean Ngu v Dennis Koppen | W | 0-2 |
| Dutch Int. - Qualif. | 2023/04/13 14:05 | Dennis Koppen v Zack Bobrowski | W | 2-0 |
| Dutch Int. - Qualif. | 2023/04/13 08:20 | Edison, Keith Mark v Dennis Koppen | W | 0-2 |
| Slovenia Future Series | 2022/11/25 15:20 | Mateusz Danielak v Dennis Koppen | L | 2-1 |
| Hungarian Int. Qual | 2022/11/02 12:00 | Cholan Kayan v Dennis Koppen | L | 2-0 |
| Dutch Open | 2022/10/13 08:35 | Burestedt, Felix v Dennis Koppen | L | 2-0 |
| Dutch Open (GP) 2017, Qualification | 2022/10/12 08:45 | Dennis Koppen v Aaron Sonnenschein | W | 2-1 |
| Spanish Int. | 2022/09/13 13:40 | Dennis Koppen v Sacha Leveque | L | 0-2 |