| Challenger Busan Qual | 2017/05/13 05:50 | Yunseong Chung v Oh, Seong-Gook | 6-4,6-7,3-6 |
| ITF Korea F4 | 2017/06/20 04:15 | Yunseong Chung v Lee, Dong-Kyu | 6-3,6-2 |
| ITF Korea F3 | 2017/06/15 01:00 | Yunseong Chung v Yoo, Daniel | 5-7,4-6 |
| ITF Korea F3 | 2017/06/14 01:00 | Yunseong Chung v Son, Ji Hoon | 7-6,6-4 |
| ITF Korea F2 | 2017/06/08 01:00 | Yunseong Chung v Son, Ji Hoon | 6-7,6-0,6-7 |
| ITF Korea F2 | 2017/06/07 07:25 | Yunseong Chung v Lee, Tae-Woo | 6-2,6-7,6-1 |
| ITF Korea F1 | 2017/05/31 01:00 | Kim, Seong Kwan v Yunseong Chung | 5-7,6-3,6-4 |
| Challenger Busan Qual | 2017/05/13 05:50 | Yunseong Chung v Oh, Seong-Gook | 6-4,6-7,3-6 |
| Challenger Seoul | 2017/05/10 03:30 | Yunseong Chung v Hiroki Moriya | 6-4,6-7,3-6 |
| ITF Korea F4 | 2017/06/20 02:55 | Nam, Hyun Woo v Oh, Seong-Gook | 2-6,2-6 |
| ITF Korea F4 | 2017/06/19 01:00 | Oh, Seong-Gook v Kim, Hyeong Don | 6-3,6-1 |
| ITF Korea F4 | 2017/06/18 02:00 | Oh, Seong-Gook v Kang, Dong Woon | 7-5,6-4 |
| ITF Korea F3 | 2017/06/14 01:00 | Oh, Seong-Gook v Lee, Tae-Woo | 2-6,4-6 |
| Korea F3, Singles Qualifying | 2017/06/12 03:00 | Oh, Seong-Gook v Park, Jun Sang | 7-5,7-6 |
| Korea F3, Singles Qualifying | 2017/06/11 04:30 | Oh, Seong-Gook v Kim, A-Ram | 6-3,6-1 |
| Korea F3, Singles Qualifying | 2017/06/10 03:00 | Oh, Seong-Gook v Jeong, In Kyo | 6-3,6-4 |
| ITF Korea F2 Qual | 2017/06/03 03:00 | Oh, Seong-Gook v Park, Jun Sang | 4-6,2-6 |