Stadium: Center Court Round: 24 Ground: Hardcourt outdoor
| Challenger Seoul | 2019/04/29 02:00 | Ji Sung Nam v Ji Hoon Son | 6-3,6-2 |
| ITF M25 Matsuyama | 2019/04/12 01:00 | Ji Sung Nam v Gage Brymer | 3-6,3-6 |
| ITF M25 Matsuyama | 2019/04/09 04:55 | Ji Sung Nam v Mark Whitehouse | 7-6,6-2 |
| ITF M15 Kashiwa | 2019/04/03 06:15 | Jumpei Yamasaki v Ji Sung Nam | 6-3,2-6,7-6 |
| ITF M15 Nishi-Tokyo | 2019/03/15 02:20 | Hiroyasu Ehara v Ji Sung Nam | 6-3,3-6,7-6 |
| ITF M15 Nishi-Tokyo | 2019/03/14 01:00 | Min-Kyu Song v Ji Sung Nam | 4-6,3-6 |
| ITF M15 Nishi-Tokyo | 2019/03/13 03:50 | Yunosuke Tanaka v Ji Sung Nam | 6-4,1-6,5-7 |
| ITF M15 Nishi-Tama | 2019/03/10 01:00 | Shintaro Imai v Ji Sung Nam | 6-2,6-2 |
| Challenger Nanchang | 2019/04/24 04:15 | Duckhee Lee v Goncalo Oliveira | 3-6,2-6 |
| Challenger Taipei | 2019/04/08 03:20 | Kaichi Uchida v Duckhee Lee | 6-4,6-4 |
| Challenger Shenzhen | 2019/03/15 09:00 | Brayden Schnur v Duckhee Lee | 6-4,4-6,7-5 |
| Challenger Shenzhen | 2019/03/14 10:55 | Zhe Li v Duckhee Lee | 3-6,3-6 |
| Challenger Shenzhen | 2019/03/12 07:20 | Duckhee Lee v Yuichi Sugita | 6-3,6-4 |
| Challenger Shenzhen | 2019/03/11 03:50 | Zihao Xia v Duckhee Lee | 3-6,1-6 |
| Challenger Zhuhai | 2019/03/04 05:25 | Baptiste Crepatte v Duckhee Lee | 6-3,7-6 |
| Challenger Yokohama | 2019/03/01 02:00 | Duckhee Lee v Soonwoo Kwon | 1-6,0-6 |