Stadium: Court 2 Round: 27 Ground: Hardcourt outdoor
| Challenger Kyoto | 2017/02/21 01:30 | Tatsuma Ito v Shuichi Sekiguchi | 6-2,6-3 |
| Challenger Nanchang | 2016/09/12 02:00 | Tatsuma Ito v Shuichi Sekiguchi | 6-3,1-6,7-6 |
| Challenger Chengdu | 2019/08/01 07:45 | Goncalo Oliveira v Shuichi Sekiguchi | 4-6,6-3,4-6 |
| Challenger Chengdu | 2019/07/31 08:55 | Shuichi Sekiguchi v Tsung-Hua Yang | 6-4,6-4 |
| Challenger Chengdu | 2019/07/29 10:30 | Weiqiang Zheng v Shuichi Sekiguchi | 5-7,1-6 |
| Challenger Nur-Sultan | 2019/07/18 05:00 | Egor Gerasimov v Shuichi Sekiguchi | 6-2,6-0 |
| Challenger Nur-Sultan | 2019/07/16 05:00 | Shuichi Sekiguchi v Zhizhen Zhang | 7-5,6-4 |
| Challenger Nur-Sultan | 2019/07/15 06:45 | Shuichi Sekiguchi v Dostanbek Tashbulatov | 6-3,6-1 |
| Challenger Fergana | 2019/06/17 07:25 | Shuichi Sekiguchi v Makoto Ochi | 6-4,6-4 |
| ITF Hongkong - M25 | 2019/06/09 04:00 | Shintaro Imai v Shuichi Sekiguchi | 6-2,6-1 |
| Challenger Chengdu | 2019/08/01 06:15 | Matthew Romios v Tatsuma Ito | 2-6,1-6 |
| Challenger Chengdu | 2019/07/30 05:10 | Makoto Ochi v Tatsuma Ito | 4-6,3-6 |
| ATP Newport | 2019/07/14 15:00 | Tatsuma Ito v John-Patrick Smith | 2-6,6-3,3-6 |
| Wimbledon | 2019/06/24 15:05 | Steven Diez v Tatsuma Ito | 6-4,6-1 |
| Challenger Ilkley | 2019/06/18 10:00 | Tatsuma Ito v Ruben Bemelmans | 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 | Marcel Granollers v Tatsuma Ito | 3-6,5-7 |
| Challenger Nottingham | 2019/06/11 17:15 | Tatsuma Ito v Jason Kubler | 6-4,6-4 |