Stadium: Court 2 Round: 25 Ground: Hardcourt outdoor
| Challenger Busan Qual | 2018/05/12 02:15 | Jeamoon Lee v Seong-Gook Oh | 7-6,6-3 |
| Challenger Seoul Qual | 2018/04/28 02:50 | Ji Hoon Son v Seong-Gook Oh | 6-3,6-3 |
| ITF China F1 | 2018/01/11 02:30 | Seong-Gook Oh v Shinji Hazawa | 3-6,4-6 |
| ITF China F1 | 2018/01/08 03:05 | Seong-Gook Oh v Yuanfeng Li | 7-6,6-2 |
| Challenger Toyota Qual | 2017/11/11 00:30 | Seong-Gook Oh v Yuya Kibi | 3-6,1-6 |
| ITF India F8 | 2017/09/15 04:30 | Seong-Gook Oh v Colin Van Beem | 6-7,6-1,4-6 |
| ITF India F8 | 2017/09/14 05:00 | Seong-Gook Oh v Clement Larriere | 6-0,1-6,6-4 |
| ITF India F8 | 2017/09/13 07:00 | Jui-Chen Hung v Seong-Gook Oh | 2-6,2-6 |
| ITF Korea F4 | 2017/06/20 02:30 | Jeamoon Lee v Jae-Won Choi | 6-1,6-3 |
| ITF Korea F3 Qual | 2017/06/10 02:00 | Dukyoung Kim v Jae-Won Choi | 6-4,6-4 |
| ITF Korea F2 | 2017/06/06 01:00 | Jae-Won Choi v Hong Chung | 2-6,0-6 |
| ITF Korea F1 | 2017/06/01 03:05 | Jae-Won Choi v Seong Chan Hong | 3-6,2-6 |
| ITF Korea F1 | 2017/05/30 01:00 | Jae-Won Choi v Seungri Choi | 6-3,6-1 |
| ITF Korea F8 | 2016/09/03 01:00 | Jae-Won Choi v Dong-Hak Sin | 4-6,5-7 |
| ITF Korea F7 | 2016/08/30 01:30 | Katsuki Nagao v Jae-Won Choi | 6-3,7-6 |
| ITF Korea F8 | 2016/08/29 01:30 | Jae-Won Choi v Chan-Yeong Oh | 6-3,6-1 |