| Challenger Gimcheon Qual | 2018/05/05 06:25 | Jinseok Yu v Woobin Shin | 6-2,6-2 |
| ITF Korea F3 Qual | 2018/06/16 02:00 | Ilsang Yoon v Dong Ju Kim | 6-2,6-2 |
| Challenger Busan Qual | 2018/05/12 01:00 | Dong Ju Kim v Tae-Woo Lee | 4-6,4-6 |
| Challenger Gimcheon Qual | 2018/05/05 06:00 | Young Seok Kim v Dong Ju Kim | 6-1,6-3 |
| Challenger Seoul Qual | 2018/04/28 01:30 | Sanhui Shin v Dong Ju Kim | 6-4,6-4 |
| ITF Korea F5 | 2017/06/28 04:40 | Dong Ju Kim v Hyun-Woo Nam | 0-6,4-6 |
| ITF Korea F5 | 2017/06/27 01:30 | Sungbeen Sim v Dong Ju Kim | 3-6,6-3,2-6 |