Stadium: Court 2 Round: 25
| ITF Korea F8 | 2016/08/26 03:00 | Kim, Young Seok v Nam, Ji Sung | 2-6,3-6 |
| ITF Korea F1 | 2018/06/06 02:50 | Kim, Young Seok v Jae Hwan Kim | 4-6,4-6 |
| Challenger - Busan | 2018/05/15 02:00 | Kim, Young Seok v Marcos Giron | 3-6,3-6 |
| Challenger Gimcheon Qual | 2018/05/06 04:30 | Renta Tokuda v Kim, Young Seok | 6-3,6-2 |
| Challenger Gimcheon Qual | 2018/05/05 06:00 | Kim, Young Seok v Dong Ju Kim | 6-1,6-3 |
| Challenger Seoul | 2018/05/01 04:35 | Jordan Thompson v Kim, Young Seok | 6-1,6-2 |
| ITF Thailand F12 Qual | 2017/12/10 03:00 | Kim, Young Seok v Jeong, Young-Hoon | 4-6,3-6 |
| ITF Thailand F11 | 2017/12/05 05:05 | Alexey Vatutin v Kim, Young Seok | 6-1,3-6,7-6 |
| ITF Thailand F11 Qual | 2017/12/04 03:00 | Kim, Young Seok v Boyer, Dusty H | 6-3,6-4 |
| ITF Korea F1 | 2018/06/08 02:00 | Nam, Ji Sung v Lim, Yong-Kyu | 1-6,2-6 |
| ITF Korea F1 | 2018/06/06 02:15 | Nam, Ji Sung v Yoo, Daniel | 6-4,6-3 |
| ITF Vietnam F3 | 2018/05/20 03:00 | Nam, Ji Sung v Isarow, Pruchya | 6-4,6-2 |
| ITF Vietnam F3 | 2018/05/18 03:00 | Ji Hoon Son v Nam, Ji Sung | 1-6,2-6 |
| ITF Vietnam F3 | 2018/05/17 03:00 | Nam, Ji Sung v Abhinav Sanjeev Shanmugam | 7-6,6-2 |
| ITF Vietnam F3 | 2018/05/16 05:30 | Rio Noguchi v Nam, Ji Sung | 3-6,1-6 |
| ITF Vietnam F3 | 2018/05/15 04:55 | Bybel, Nicholas v Nam, Ji Sung | 4-6,2-6 |
| ITF Vietnam F2 | 2018/05/13 04:00 | Rio Noguchi v Nam, Ji Sung | 7-6,6-3 |