Stadium: Centre Court Round: 28 Ground: Hardcourt outdoor
| ITF M25 Wuhan | 2019/05/06 02:00 | Kazuki Nishiwaki v Jianhui Li | 5-7,6-2,6-10 |
| ITF M15 Wuhan | 2019/05/02 02:00 | Kazuki Nishiwaki v Sora Fukuda | 2-6,1-6 |
| ITF M15 Wuhan | 2019/05/01 03:50 | Xin Gao v Kazuki Nishiwaki | 6-2,3-6,3-6 |
| ITF M25 Matsuyama | 2019/04/10 07:40 | Rinky Hijikata v Kazuki Nishiwaki | 6-3,6-4 |
| ITF M15 Kashiwa | 2019/04/01 06:00 | Kuan-Yi Lee v Kazuki Nishiwaki | 6-4,6-4 |
| ITF M15 Kashiwa | 2019/04/01 00:00 | Daisuke Sumizawa v Kazuki Nishiwaki | 6-2,2-6,8-10 |
| ITF M15 Tsukuba | 2019/03/27 01:00 | Makoto Ochi v Kazuki Nishiwaki | 6-3,6-1 |
| ITF M15 Kofu | 2019/03/20 05:10 | Mick Veldheer v Kazuki Nishiwaki | 4-6,6-1,6-4 |
| Challenger Sarasota | 2019/04/15 18:40 | Daniel Nguyen v Ryan Shane | 6-7,5-7 |
| Challenger Zhangjiagang | 2019/03/19 05:45 | Daniel Nguyen v Lorenzo Giustino | 0-6,3-6 |
| Challenger Zhangjiagang | 2019/03/18 03:55 | Maverick Banes v Daniel Nguyen | 4-6,3-6 |
| Challenger Yokohama | 2019/02/26 03:30 | Yuichi Sugita v Daniel Nguyen | 2-6,6-4,7-5 |
| Challenger Yokohama | 2019/02/25 04:10 | Blake Ellis v Daniel Nguyen | 6-3,5-7,5-7 |
| Challenger Morelos | 2019/02/18 21:15 | Gerardo L Villasenor v Daniel Nguyen | 6-3,6-3 |
| Challenger Chennai | 2019/02/04 04:30 | Daniel Nguyen v Daniel Altmaier | 3-6,2-6 |
| Challenger Launceston | 2019/01/29 02:35 | Pedro Martinez v Daniel Nguyen | 7-5,7-6 |