Stadium: Court 2 Round: 62 Ground: Hardcourt outdoor
| Challenger Gwangju | 2019/05/14 03:30 | Yan Bai v Ji Hoon Son | 7-6,2-6,6-3 |
| Challenger Seoul | 2019/04/29 02:00 | Ji Sung Nam v Ji Hoon Son | 6-3,6-2 |
| ITF Korea F5 | 2018/08/24 01:15 | Ji Sung Nam v Ji Hoon Son | 6-4,6-2 |
| ITF Korea F5 | 2018/08/23 05:15 | Woo Hyeok Jang v Ji Hoon Son | 6-7,1-6 |
| ITF Korea F5 | 2018/08/21 01:00 | Ren Nakamura v Ji Hoon Son | 6-4,4-6,3-6 |
| Challenger Gwangju | 2018/08/14 06:30 | Bradley Mousley v Ji Hoon Son | 6-3,6-2 |
| Challenger Gwangju Qual | 2018/08/13 01:00 | Yuya Kibi v Ji Hoon Son | 3-6,4-6 |
| Challenger Gwangju Qual | 2018/08/11 03:35 | Ji Hoon Son v Xin Gao | 7-5,6-3 |
| ITF M15 Changwon | 2019/10/16 00:45 | Geun Jun Kim v Sora Fukuda | 4-6,3-6 |
| ITF M15 Hua Hin | 2019/08/27 04:00 | Ti Chen v Geun Jun Kim | 4-6,7-5,10-2 |
| ITF M15 Anseong | 2019/06/26 01:00 | Yeongseok Jeong v Geun Jun Kim | 6-3,6-1 |
| ITF M15 Anseong | 2019/06/25 02:30 | Winter Meagher v Geun Jun Kim | 3-6,4-6 |
| ITF M15 Anseong | 2019/06/24 03:00 | Sung Jun Park v Geun Jun Kim | 3-6,3-6 |
| ITF M15 Gimcheon | 2019/06/11 02:35 | Geun Jun Kim v Jeong Heon Lee | 6-2,1-6,4-10 |
| ITF M15 Gimcheon | 2019/06/10 04:25 | Geun Jun Kim v Chen Chang | 6-1,6-1 |
| ITF M15 Daegu | 2019/06/05 04:35 | Geun Jun Kim v Taisei Ichikawa | 1-6,2-6 |