| Ungern Int. - Kval | 2019/10/30 17:10 | Leon Seiwald v Tobias Kuenzi | L | 0-2 |
| Polen - Int. | 2019/09/21 09:55 | Ivan Rusev v Leon Seiwald | L | 2-0 |
| Polen - Int. | 2019/09/20 10:20 | Leon Seiwald v Joonas Korhonen | W | 2-1 |
| Belgian Int. | 2019/09/12 13:00 | Luis Enrique Penalver v Leon Seiwald | L | 2-1 |
| Kharkiv Int. - Kval | 2019/09/04 11:30 | Leon Seiwald v Gergo Pytel | L | 1-2 |
| Belarus Int. | 2019/08/30 10:40 | Raul Must v Leon Seiwald | L | 2-1 |
| Slovenia Int. - Kval | 2019/05/15 08:30 | Leon Seiwald v B.M. Rahul Bharadwaj | L | 0-2 |
| Swiss Open - Damdubbel - Kval | 2019/02/21 09:10 | Bobby Setiabudi v Leon Seiwald | L | 2-0 |