Stadium: Court F Round: 28 Ground: Hardcourt outdoor
| Challenger Seoul Qual | 2017/05/06 02:20 | Daniel Nguyen v Takuto Niki | 2-6,6-1,6-2 |
| ITF Japan F1 | 2018/03/09 02:00 | Naoki Nakagawa v Daniel Nguyen | 6-3,3-6,5-7 |
| ITF Japan F1 | 2018/03/08 05:40 | Rio Noguchi v Daniel Nguyen | 4-6,3-6 |
| ITF Japan F1 | 2018/03/07 05:30 | Shoma Kato v Daniel Nguyen | 0-6,2-6 |
| Challenger Yokohama | 2018/03/01 02:00 | Daniel Nguyen v Stephane Robert | 5-7,0-6 |
| Challenger Yokohama | 2018/02/27 05:35 | Daniel Nguyen v Yosuke Watanuki | 6-2,6-4 |
| Challenger Yokohama Qual | 2018/02/26 01:00 | Hiroki Moriya v Daniel Nguyen | 6-2,6-3 |
| Challenger Yokohama Qual | 2018/02/25 02:20 | Yuta Shimizu v Daniel Nguyen | 6-4,5-7,2-6 |
| Challenger Yokohama Qual | 2018/02/24 06:35 | Nasa Hatakeyama v Daniel Nguyen | 1-6,3-6 |
| ITF Japan F1 | 2018/03/09 02:00 | Takuto Niki v Soichiro Moritani | 6-1,6-4 |
| ITF Japan F1 | 2018/03/08 03:10 | Takuto Niki v Yuya Kibi | 6-3,7-5 |
| ITF Japan F1 | 2018/03/07 04:45 | Takuto Niki v Naoya Maesaki | 6-2,6-7,6-2 |
| Challenger Yokohama Qual | 2018/02/25 02:35 | Yunseong Chung v Takuto Niki | 6-7,6-3,6-3 |
| Challenger Yokohama Qual | 2018/02/24 07:05 | Takuto Niki v N.Sriram Balaji | 3-6,7-6,7-5 |
| Challenger Kyoto Qual | 2018/02/19 03:45 | Blake Ellis v Takuto Niki | 6-3,6-4 |
| Challenger Kyoto Qual | 2018/02/18 06:05 | Masaki Osafune v Takuto Niki | 3-6,2-6 |
| Challenger Kyoto Qual | 2018/02/17 07:50 | Kaito Itsusaki v Takuto Niki | 4-6,0-6 |