Stadium: Court 1 Round: 25 Ground: Hardcourt outdoor
| ITF M25 Skopje | 2021/09/29 11:50 | Aldin Setkic v Jumpei Yamasaki | 7-5,6-4 |
| ITF M15 Monastir | 2021/08/26 07:30 | Kyle Seelig v Jumpei Yamasaki | 6-0,7-5 |
| ITF M15 Monastir | 2021/08/25 07:30 | Keisuke Saitoh v Jumpei Yamasaki | 1-6,1-6 |
| ITF M15 Monastir | 2021/08/18 07:30 | Mateo Nicolas Martinez v Jumpei Yamasaki | 5-7,6-1,7-5 |
| ITF M15 Monastir | 2021/08/11 18:25 | Sho Shimabukuro v Jumpei Yamasaki | 6-3,6-2 |
| ITF M25 Decatur | 2021/08/05 17:55 | Jumpei Yamasaki v Yunseong Chung | 2-6,2-6 |
| ITF M25 Decatur | 2021/08/04 21:50 | Aleksandar Kovacevic v Jumpei Yamasaki | 4-6,6-3,3-6 |
| ITF M25 Decatur | 2021/08/03 17:10 | Jumpei Yamasaki v Stefan Dostanic | 6-4,6-4 |
| Challenger Lisbon | 2021/09/28 09:00 | Sebastian Fanselow v Nikola Milojevic | 4-6,4-6 |
| Challenger Lisbon | 2021/09/27 09:00 | Jacopo Berrettini v Sebastian Fanselow | 6-4,5-7,2-6 |
| Challenger Lisbon | 2021/09/26 09:00 | Marco Bortolotti v Sebastian Fanselow | 2-6,2-6 |
| Challenger Braga | 2021/09/20 09:00 | Nikolas Sanchez Izquierdo v Sebastian Fanselow | 6-4,1-6,6-3 |
| Challenger Braga | 2021/09/19 10:25 | Jaime Faria v Sebastian Fanselow | 0-6,2-6 |
| ITF M25 Sintra | 2021/09/15 15:35 | Adria Soriano Barrera v Sebastian Fanselow | 6-4,6-4 |
| ITF M25 Sintra | 2021/09/08 10:40 | Luca Potenza v Sebastian Fanselow | 6-4,6-4 |
| ITF M25 Bagnères-de-Bigorre | 2021/09/01 07:30 | Millen Hurrion v Sebastian Fanselow | 2-6,7-5,7-6 |