Stadium: Cancha 3 Round: 25 Ground: Hardcourt outdoor
| Challenger Salinas | 2021/04/21 15:00 | Shuichi Sekiguchi v Nicolas Jarry | 1-6,2-6 |
| Challenger Salinas | 2021/04/19 16:00 | Hiroki Moriya v Shuichi Sekiguchi | 1-6,6-7 |
| Challenger Orlando | 2021/04/12 15:30 | Altug Celikbilek v Shuichi Sekiguchi | 4-6,6-4,7-5 |
| Challenger Cleveland | 2021/03/16 18:40 | Alexis Galarneau v Shuichi Sekiguchi | 6-3,6-1 |
| Challenger St. Petersburg | 2021/03/08 10:00 | Duje Ajdukovic v Shuichi Sekiguchi | 7-5,6-2 |
| Challenger St. Petersburg | 2021/03/01 13:45 | Shuichi Sekiguchi v Cem Ilkel | 3-6,2-6 |
| ITF M25 Rodez | 2020/10/14 12:20 | Maxime Hamou v Shuichi Sekiguchi | 4-6,7-6,7-6 |
| ITF M25 Porto | 2020/10/03 09:00 | Shuichi Sekiguchi v Gastao Elias | 2-6,3-6 |
| Challenger Tallahassee | 2021/04/21 20:00 | Pedro Sakamoto v Mikael Torpegaard | 0-6,6-3,1-6 |
| Challenger Tallahassee | 2021/04/19 17:00 | Prajnesh Gunneswaran v Pedro Sakamoto | 2-6,6-2,4-6 |
| Challenger Santiago | 2021/03/16 15:15 | Nicolas Alvarez v Pedro Sakamoto | 3-6,6-4,6-3 |
| ATP Santiago | 2021/03/07 14:00 | Alejandro Tabilo v Pedro Sakamoto | 7-6,6-4 |
| ATP Santiago | 2021/03/06 13:00 | Rafael Matos v Pedro Sakamoto | 3-6,1-6 |
| ATP Buenos Aires | 2021/02/28 14:00 | Pedro Sakamoto v Agustin Velotti | 3-6,4-6 |
| ATP Cordoba | 2021/02/22 17:30 | Facundo Bagnis v Pedro Sakamoto | 6-2,6-4 |
| ATP Cordoba | 2021/02/21 16:20 | Renzo Olivo v Pedro Sakamoto | 2-6,5-7 |