| Swiss Open WD Qual | 12/13 08:30 | 1 | Christopher Grimley v Leon Seiwald | W | 0-2 | |
| Giraldilla Int. XD | 11/02 09:55 | 1 | Jesper Toft v Leon Seiwald | L | 2-1 | |
| Swiss Open WD Qual | 09/27 12:10 | 1 | Artyom Savatyugin v Leon Seiwald | W | 0-2 | |
| Polish Int. | 09/22 12:45 | 1 | Likka Heino v Leon Seiwald | L | 2-1 | |
| Polish Int. | 09/20 14:00 | 1 | Jonathan Dolan v Leon Seiwald | W | 0-2 | |
| Giraldilla Int. XD | 08/30 07:00 | 1 | Leon Seiwald v Jaromir Janacek | W | 2-0 | |
| Swiss Open WD Qual | 05/10 08:00 | 1 | Leon Seiwald v Sebastian Bugtrup | L | 1-2 | |
| Swiss Open WD Qual | 03/08 11:30 | 1 | Marcus Loo v Leon Seiwald | W | 1-2 | |
| Swiss Open WD Qual | 02/21 10:40 | 1 | David Peng v Leon Seiwald | L | 2-1 | |
| Swiss Open WD Qual | 12/05 14:26 | - | Leon Seiwald v Peter Correl | L | 1-2 | |
| Indonesia Masters XD | 05/22 02:20 | 1 | Zin Rei Ryan Ng v Leon Seiwald | L | 2-1 | |
| Giraldilla Int. XD | 03/09 21:47 | - | Douglas Lidman v Leon Seiwald | L | 2-0 |