| Slovak Open Qual | 2024/04/17 14:35 | Tauri Kilk v Leon Seiwald | L | 2-0 |
| Slovak Open Qual | 2024/04/17 07:45 | Leon Seiwald v James Robertson | W | 2-0 |
| Euro Mixed Team Champs | 2020/12/10 17:30 | Milan Ludik v Leon Seiwald | W | 0-2 |
| SaarLorLux Open | 2020/10/27 09:00 | Leon Seiwald v Kim Bruun | L | 0-2 |
| Slovak Open | 2020/02/27 15:30 | Jan Louda v Leon Seiwald | L | 2-0 |
| Austrian Open Qual | 2020/02/19 12:15 | Leon Seiwald v Rahul Yadav Chittaboina | L | 1-2 |
| European Team Championships | 2020/02/13 18:00 | Leon Seiwald v Joshua Magee | W | 2-1 |
| European Team Championships | 2020/02/12 19:00 | Leon Seiwald v Mateusz Dubowski | W | 2-1 |