| Syed Modi Int. | 2019/11/27 11:40 | Kwang Hee Heo v Kai Schaefer | W | 2-0 |
| Indonesia Masters | 2021/11/16 10:10 | Toma Junior Popov v Kwang Hee Heo | L | 2-0 |
| French Open | 2021/10/30 09:00 | Tien Chen Chou v Kwang Hee Heo | L | 2-0 |
| French Open | 2021/10/29 12:30 | Lakshya Sen v Kwang Hee Heo | W | 0-2 |
| French Open | 2021/10/28 14:40 | Tzu Wei Wang v Kwang Hee Heo | W | 0-2 |
| Denmark Open | 2021/10/19 13:45 | Kanta Tsuneyama v Kwang Hee Heo | L | 2-1 |
| Thomas Cup | 2021/10/15 06:30 | Kwang Hee Heo v Kento Momota | W | 2-0 |
| Thomas Cup | 2021/10/13 17:00 | Viktor Axelsen v Kwang Hee Heo | L | 2-0 |
| Thomas Cup | 2021/10/11 17:00 | Kwang Hee Heo v Toma Junior Popov | W | 2-1 |
| Belgian International | 2021/10/28 08:30 | Ade Resky Dwicahyo v Kai Schaefer | L | 2-1 |
| Olympische Spiele 2020 - Herren | 2021/07/27 01:40 | Toby Penty v Kai Schaefer | L | 2-0 |
| Olympische Spiele 2020 - Herren | 2021/07/25 11:00 | Kantaphon Wangcharoen v Kai Schaefer | L | 2-0 |
| Spain International | 2021/06/17 15:00 | Ivan Rusev v Kai Schaefer | L | 2-0 |
| Spain Masters | 2021/05/19 11:20 | Kai Schaefer v Lucas Claerbout | L | 1-2 |
| Portuguese Int. | 2021/05/07 14:30 | Kai Schaefer v Johnnie Torjussen | L | 0-2 |
| Europameisterschaft | 2021/04/28 12:20 | Kai Schaefer v Anders Antonsen | L | 0-2 |
| Orleans Masters | 2021/03/25 11:30 | Kai Schaefer v Ditlev Jaeger Holm | L | 0-2 |