Stadium: Court 1 Round: 46
| Challenger Seoul Qual | 2017/05/06 02:20 | Daniel Nguyen v Takuto Niki | 2-6,6-1,6-2 |
| Challenger Gimcheon Qual | 2017/05/01 02:00 | Takuto Niki v Hubert Hurkacz | 3-6,4-6 |
| Challenger Gimcheon Qual | 2017/04/30 03:45 | Takuto Niki v Ki Su Jung | 6-1,6-2 |
| Challenger Gimcheon Qual | 2017/04/29 05:10 | Takuto Niki v Hiroyasu Ehara | 6-1,6-4 |
| ITF Japan F5 | 2017/04/07 04:31 | Masato Shiga v Takuto Niki | 6-2,0-6,6-4 |
| ITF Japan F5 | 2017/04/07 04:30 | Masato Shiga v Takuto Niki | 6-2,0-6,6-4 |
| ITF Japan F5 | 2017/04/05 02:50 | Chan-Yeong Oh v Takuto Niki | 4-6,6-3,2-6 |
| ITF Japan F5 | 2017/04/04 00:30 | Yuichi Ito v Takuto Niki | 3-6,4-6 |
| Challenger Busan Qual | 2017/05/13 05:50 | Yunseong Chung v Seong-Gook Oh | 6-4,6-7,3-6 |
| ITF Korea F8 | 2016/09/03 01:00 | Seon Yong Han v Seong-Gook Oh | 6-4,6-1 |
| ITF Japan F7 Qual | 2016/06/04 01:00 | Yuga Tashiro v Seong-Gook Oh | 6-2,6-2 |
| ITF Guam F1 | 2016/05/25 01:35 | Seong-Gook Oh v Sho Katayama | 4-6,1-6 |
| ITF Guam F1 | 2016/05/23 02:25 | Seong-Gook Oh v Ren Nakamura | 6-4,6-4 |
| ITF Guam F1 | 2016/05/22 00:00 | Seong-Gook Oh v Kennosuke Nouchi | 6-4,6-1 |
| ITF China F6 Qual | 2016/05/09 02:00 | Yusuke Takahashi v Seong-Gook Oh | 6-1,6-4 |
| ITF China F6 Qual | 2016/05/08 02:00 | Jianhui Li v Seong-Gook Oh | 6-7,4-6 |