Stadium: Court 2 Round: 27 Ground: Hardcourt outdoor
| Kyoto, Japan | 2017/02/21 01:30 | Tatsuma Ito v Sekiguchi, Shuichi | 6-2,6-3 |
| Nanchang, China | 2016/09/12 02:00 | Tatsuma Ito v Sekiguchi, Shuichi | 6-3,1-6,7-6 |
| Chengdu, China | 2019/08/01 07:45 | Goncalo Oliveira v Sekiguchi, Shuichi | 4-6,6-3,4-6 |
| Chengdu, China | 2019/07/31 08:55 | Sekiguchi, Shuichi v Yang, Tsung-Hua | 6-4,6-4 |
| Chengdu, China | 2019/07/29 10:30 | Zheng, Weiqiang v Sekiguchi, Shuichi | 5-7,1-6 |
| Nur Sultan, Kazakhstan | 2019/07/18 05:00 | Egor Gerasimov v Sekiguchi, Shuichi | 6-2,6-0 |
| Nur Sultan, Kazakhstan | 2019/07/16 05:00 | Sekiguchi, Shuichi v Zhizhen Zhang | 7-5,6-4 |
| Nur Sultan, Kazakhstan | 2019/07/15 06:45 | Sekiguchi, Shuichi v Tashbulatov, Dostanbek | 6-3,6-1 |
| Fergana, Uzbekistan | 2019/06/17 07:25 | Sekiguchi, Shuichi v Makoto Ochi | 6-4,6-4 |
| Hong Kong, Simples M-ITF-HKG-04A | 2019/06/09 04:00 | Shintaro Imai v Sekiguchi, Shuichi | 6-2,6-1 |
| Chengdu, China | 2019/08/01 06:15 | Romios, Matthew Christopher v Tatsuma Ito | 2-6,1-6 |
| Chengdu, China | 2019/07/30 05:10 | Makoto Ochi v Tatsuma Ito | 4-6,3-6 |
| Newport, USA | 2019/07/14 15:00 | Tatsuma Ito v Smith, John-Patrick | 2-6,6-3,3-6 |
| Wimbledon, London, Great Britain | 2019/06/24 15:05 | Steven Diez v Tatsuma Ito | 6-4,6-1 |
| Ilkley, Great Britain | 2019/06/18 10:00 | Tatsuma Ito v Bemelmans, Ruben | 7-6,3-6,4-6 |
| Challenger - Nottingham | 2019/06/14 11:00 | Tatsuma Ito v Lukas Rosol | 4-6,7-6,3-6 |
| Challenger - Nottingham | 2019/06/13 12:00 | Granollers, Marcel v Tatsuma Ito | 3-6,5-7 |
| Challenger - Nottingham | 2019/06/11 17:15 | Tatsuma Ito v Jason Kubler | 6-4,6-4 |