Stadium: Court 2 Round: 25 Ground: Hardcourt outdoor
| Challenger Busan | 2018/05/15 05:50 | Max Purcell v Jung-Woong Na | 6-4,6-1 |
| Challenger Gimcheon Qual | 2018/05/05 05:20 | Jacob Grills v Jung-Woong Na | 5-7,6-4,6-3 |
| Challenger Seoul Qual | 2018/04/29 02:00 | Jung-Woong Na v Makoto Ochi | 2-6,4-6 |
| Challenger Seoul Qual | 2018/04/28 03:05 | Jung-Woong Na v Tae-Woo Lee | 6-1,6-3 |
| ITF Turkey F5 | 2018/02/08 07:30 | Jung-Woong Na v Nino Serdarusic | 1-6,2-6 |
| ITF Turkey F5 | 2018/02/06 07:30 | Razvan M Codescu v Jung-Woong Na | 3-6,0-6 |
| ITF Turkey F5 | 2018/02/05 07:30 | Jung-Woong Na v Luka Miklavcic | 6-4,6-0 |
| ITF Turkey F5 | 2018/02/04 07:30 | Jung-Woong Na v Sorin Andrei Iordache | 6-1,7-6 |
| ITF Vietnam F3 | 2018/05/18 03:00 | Ji Hoon Son v Ji Sung Nam | 1-6,2-6 |
| ITF Vietnam F3 | 2018/05/16 03:00 | Ji Hoon Son v Gary Kushnirovich | 4-6,7-6,6-1 |
| ITF Vietnam F3 | 2018/05/15 03:00 | Nam Hoang Ly v Ji Hoon Son | 1-6,4-6 |
| ITF Vietnam F2 | 2018/05/08 03:00 | Nam Hoang Ly v Ji Hoon Son | 3-6,7-5,6-0 |
| ITF Vietnam F2 | 2018/05/06 04:00 | Ji Hoon Son v Sang-Woo Noh | 6-2,6-1 |
| Challenger Seoul | 2018/05/03 08:30 | Jordan Thompson v Ji Hoon Son | 7-5,7-6 |
| Challenger Seoul Qual | 2018/04/30 03:00 | Wishaya Trongcharoenchaikul v Ji Hoon Son | 6-7,4-6 |
| Challenger Seoul Qual | 2018/04/29 02:00 | Ji Hoon Son v Shuichi Sekiguchi | 6-2,7-6 |