| Swiss Open WD Qual | 2019/01/15 08:45 | Sitthikom Thammasin v Zii Jia Lee | L | 0-2 |
| Swiss Open WD Qual | 2019/01/15 03:09 | Sitthikom Thammasin v Junpeng Zhao | W | 2-1 |
| Thailand Masters | 2019/01/10 08:00 | Sitthikom Thammasin v Firman Abdul Kholik | L | 0-2 |
| Thailand Masters | 2019/01/09 05:20 | Kantaphon Wangcharoen v Sitthikom Thammasin | W | 0-2 |
| Giraldilla Int. XD | 2018/11/30 06:50 | Joo Ven Soong v Sitthikom Thammasin | W | 1-2 |
| Giraldilla Int. XD | 2018/11/29 09:00 | Sitthikom Thammasin v Misha Zilberman | W | 2-1 |
| Giraldilla Int. XD | 2018/11/28 10:30 | Sitthikom Thammasin v Firman Abdul Kholik | W | 2-1 |
| Giraldilla Int. XD | 2018/11/24 09:40 | Sitthikom Thammasin v Guangzu Lu | L | 1-2 |
| Indonesia Masters XD | 2019/01/16 11:05 | Viktor Axelsen v Kazumasa Sakai | L | 2-0 |
| Indonesia Masters XD | 2018/11/14 12:45 | Jonatan Christie v Kazumasa Sakai | L | 2-0 |
| All England Open | 2018/11/08 04:50 | Kazumasa Sakai v Yuqi Shi | L | 0-2 |
| All England Open | 2018/11/07 06:15 | Suppanyu Avihingsanon v Kazumasa Sakai | W | 1-2 |
| French Open | 2018/10/25 12:40 | Kento Momota v Kazumasa Sakai | L | 2-0 |
| French Open | 2018/10/24 11:00 | Kazumasa Sakai v Dan Lin | W | 2-1 |
| Denmark Open | 2018/10/17 15:40 | Viktor Axelsen v Kazumasa Sakai | L | 2-0 |
| Indonesia Masters XD | 2018/09/27 04:20 | Kazumasa Sakai v Tien Chen Chou | L | 0-2 |