Stadium: Court 4 Round: 25 Ground: Hardcourt outdoor
| Challenger Seoul Qual | 2018/04/28 01:30 | Daniel Yoo v Ji Sung Nam | 2-6,2-6 |
| ITF Vietnam F3 | 2018/05/20 03:00 | Ji Sung Nam v Pruchya Isarow | 6-4,6-2 |
| ITF Vietnam F3 | 2018/05/18 03:00 | Ji Hoon Son v Ji Sung Nam | 1-6,2-6 |
| ITF Vietnam F3 | 2018/05/17 03:00 | Ji Sung Nam v Abhinav Sanjeev Shanmugam | 7-6,6-2 |
| ITF Vietnam F3 | 2018/05/16 05:30 | Rio Noguchi v Ji Sung Nam | 3-6,1-6 |
| ITF Vietnam F3 | 2018/05/15 04:55 | Nicholas Bybel v Ji Sung Nam | 4-6,2-6 |
| ITF Vietnam F2 | 2018/05/13 04:00 | Rio Noguchi v Ji Sung Nam | 7-6,6-3 |
| ITF Vietnam F2 | 2018/05/12 04:45 | Gengo Kikuchi v Ji Sung Nam | 4-6,3-6 |
| ITF Vietnam F2 | 2018/05/11 03:00 | Kelsey Stevenson v Ji Sung Nam | 6-4,2-6,1-6 |
| Challenger Busan Qual | 2018/05/12 01:00 | Luke Saville v Daniel Yoo | 6-1,6-0 |
| Challenger Gimcheon Qual | 2018/05/05 01:30 | Daniel Yoo v Ben Patael | 3-6,2-6 |
| Challenger Seoul Qual | 2018/04/28 01:30 | Daniel Yoo v Ji Sung Nam | 2-6,2-6 |
| Challenger Gwangju Qual | 2017/09/16 01:30 | Woo Hyeok Jang v Daniel Yoo | 6-4,6-4 |
| ITF Korea F5 | 2017/06/29 04:50 | Daniel Yoo v Ku Keon Kang | 3-6,3-6 |
| ITF Korea F5 | 2017/06/28 04:55 | Daniel Yoo v Ki Su Jung | 6-0,6-1 |
| ITF Korea F4 | 2017/06/20 01:00 | Daniel Yoo v Hyung-Chan Lim | 6-2,6-2 |
| ITF Korea F3 | 2017/06/16 02:00 | Daniel Yoo v Hong Chung | 3-6,0-6 |