| ITF Korea F4 | 2018/08/16 03:05 | Lee, Young Seok v Uisung Park | 2-6,0-6 |
| ITF Korea F4 | 2018/08/14 01:00 | Addison, Aaron v Lee, Young Seok | 6-0,3-6,2-6 |
| ITF Korea F4 | 2018/08/12 02:00 | Shin, Jung Ho v Lee, Young Seok | 3-6,3-6 |
| Challenger Gimcheon | 2018/05/08 05:40 | Lee, Young Seok v Makoto Ochi | 1-6,1-6 |
| ITF Korea F1 Qual | 2016/06/11 01:00 | Kim, Ji Ha v Lee, Young Seok | 3-6,7-6,6-2 |
| ITF Korea F4 | 2018/08/13 01:00 | Ku Keon Kang v Lee, Seounghun | 6-2,6-2 |
| ITF Korea F4 | 2018/08/12 02:00 | Yun, Jae Won v Lee, Seounghun | 6-3,2-6,6-7 |
| Korea F3, Singles Qualifying | 2018/06/16 01:00 | Shin, Geon Ju v Lee, Seounghun | 3-6,4-6 |
| ITF Korea F2 | 2018/06/10 05:00 | Noh, Sang-Woo v Lee, Seounghun | 6-3,6-3 |
| ITF Korea F2 | 2018/06/09 02:00 | Lee, Seounghun v Shin, Geon Ju | 6-3,6-4 |
| ITF Korea F1 | 2018/06/02 02:00 | Park, Sung Jun v Lee, Seounghun | 6-1,6-1 |
| Challenger Gwangju Qual | 2017/09/16 01:30 | Lee, Seounghun v Lee, Dae-Hee | 4-6,3-6 |
| ITF Korea F5 | 2017/06/26 01:30 | Hong, Seong Chan v Lee, Seounghun | 6-3,6-0 |