Stadium: Court 4 Round: 25 Ground: Hardcourt indoor
| ITF Korea F3 | 2018/06/24 05:00 | Yunseong Chung v Nam, Ji Sung | 6-1,6-3 |
| ITF Korea F2 | 2018/06/17 04:00 | Nam, Ji Sung v Yunseong Chung | 4-6,3-6 |
| Challenger Columbus | 2021/09/20 14:00 | Alexis Galarneau v Yunseong Chung | 4-6,4-6 |
| Challenger Columbus | 2021/09/19 18:35 | Boulais, Justin v Yunseong Chung | 6-7,3-6 |
| Winston-Salem, USA | 2021/08/21 20:10 | Yunseong Chung v Yosuke Watanuki | 3-6,6-7 |
| ITF M25 Decatur | 2021/08/06 17:10 | Yunseong Chung v Eliot Spizzirri | 4-6,4-6 |
| ITF M25 Decatur | 2021/08/05 17:55 | Jumpei Yamasaki v Yunseong Chung | 2-6,2-6 |
| ITF M25 Decatur | 2021/08/04 18:45 | Yunseong Chung v Nathan Ponwith | 6-2,6-1 |
| ITF M25 Champaign | 2021/07/28 17:25 | Yunseong Chung v Ben Shelton | 5-7,0-6 |
| Nur Sultan, Kazakhstan | 2021/07/19 10:05 | Yunseong Chung v Hugo Grenier | 7-6,3-6,1-6 |
| Coupe Davis | 2021/09/17 16:00 | Rubin Statham v Nam, Ji Sung | 2-6,2-6 |
| ITF - M15 Monastir | 2021/06/30 08:30 | Nam, Ji Sung v Moez Echargui | 3-6,4-6 |
| ITF - M15 Monastir | 2021/06/22 10:50 | Nam, Ji Sung v Rinky Hijikata | 3-6,1-6 |
| ITF - M15 Monastir | 2021/06/16 08:30 | Nam, Ji Sung v Aidan Mayo | 6-4,3-6,2-6 |
| ITF - M15 Monastir | 2021/06/11 08:30 | Nam, Ji Sung v Beale, Jeremy | 1-6,6-1,6-7 |
| ITF - M15 Monastir | 2021/06/10 08:25 | Nam, Ji Sung v Crepaldi, Erik | 6-4,7-5 |
| ITF - M15 Monastir | 2021/06/09 11:15 | Nam, Ji Sung v Badenhorst, Devin | 6-7,6-2,7-6 |
| ATP Great Ocean Road Open | 2021/02/02 01:00 | Nam, Ji Sung v Dane Sweeny | 6-7,5-7 |