| Giraldilla Int. XD | 2017/09/19 07:06 | Sakai, Kazumasa v Lee, Dong Keun | L | 0-2 |
| Indonesia Masters | 2019/10/02 12:20 | Sakai, Kazumasa v Prasetyo, Wisnu Yuli | L | 0-2 |
| Chinese Taipei Open 2019, MS | 2019/09/04 10:40 | Sakai, Kazumasa v Verma, Sourabh | L | 0-2 |
| Akita Masters 2019, MS | 2019/08/15 02:15 | Sakai, Kazumasa v Igarashi, Yu | L | 1-2 |
| Akita Masters 2019, MS | 2019/08/14 03:30 | Sakai, Kazumasa v Kodai Naraoka | W | 2-0 |
| US Open 2019, MS | 2019/07/11 21:15 | Saensomboonsuk, Tanongsak v Sakai, Kazumasa | L | 2-0 |
| US Open 2019, MS | 2019/07/10 21:15 | Lam, Timothy v Sakai, Kazumasa | W | 0-2 |
| Canada Open | 2019/07/03 17:50 | Sakai, Kazumasa v Heo, Kwang Hee | L | 0-2 |
| Australian Open | 2019/06/07 08:00 | Tzu Wei Wang v Sakai, Kazumasa | L | 2-0 |
| India PBL | 2020/01/22 13:45 | Lakshya Sen v Lee, Dong Keun | L | 2-0 |
| Korea Masters | 2019/11/20 07:00 | Lee, Dong Keun v Lin, Dan | L | 1-2 |
| Macau Open 2019, MS | 2019/10/31 05:20 | Lee, Dong Keun v Thammasin, S. | L | 0-2 |
| Macau Open 2019, MS | 2019/10/30 02:50 | June Wei Cheam v Lee, Dong Keun | W | 0-2 |
| Korea Open 2019, MS, Qualification | 2019/09/24 05:00 | Lee, Dong Keun v Kim, Donghun (1993) | L | 0-2 |
| Korea Open 2019, MS, Qualification | 2019/09/24 01:40 | Leverdez, Brice v Lee, Dong Keun | W | 1-2 |
| Chinese Taipei Open 2019, MS | 2019/09/04 08:35 | Lee, Dong Keun v Wong, Wing Ki Vincent | L | 1-2 |
| World Championships | 2019/08/20 10:00 | Sai Praneeth, B. v Lee, Dong Keun | L | 2-0 |