Stadium: Court 1 Round: 26 Ground: Hardcourt outdoor
| 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 |
| ITF M25 Decatur | 2021/08/02 15:00 | Jumpei Yamasaki v Carson Haskins | 6-1,6-2 |
| ITF M25 Champaign | 2021/07/29 17:00 | Gijs Brouwer v Jumpei Yamasaki | 6-3,6-0 |
| ITF M25 Champaign | 2021/07/28 19:10 | Martin Damm v Jumpei Yamasaki | 6-7,6-7 |
| ITF M15 Antalya | 2021/05/02 06:00 | Jumpei Yamasaki v Federico Bertuccioli | 6-2,4-6,10-6 |
| ITF M15 Antalya | 2021/04/27 10:30 | Mick Veldheer v Jumpei Yamasaki | 4-6,6-1,6-0 |
| ITF M15 Antalya | 2021/04/20 07:00 | Jumpei Yamasaki v Bogdan Bobrov | 3-6,5-7 |
| ITF M25 Decatur | 2021/08/04 18:45 | Yunseong Chung v Nathan Ponwith | 6-2,6-1 |
| ITF M25 Champaign | 2021/07/28 17:25 | Yunseong Chung v Ben Shelton | 5-7,0-6 |
| Challenger Nur-Sultan | 2021/07/19 10:05 | Yunseong Chung v Hugo Grenier | 7-6,3-6,1-6 |
| Challenger Nur-Sultan | 2021/07/15 06:00 | Roman Safiullin v Yunseong Chung | 6-3,6-4 |
| Challenger Nur-Sultan | 2021/07/13 07:15 | Yunseong Chung v Yan Bondarevskiy | 6-3,6-4 |
| ITF M15 Monastir | 2021/05/27 08:30 | Yuta Kikuchi v Yunseong Chung | 2-6,6-3,1-6 |
| ITF M15 Monastir | 2021/05/26 09:30 | Louis Tessa v Yunseong Chung | 1-6,0-6 |
| ITF M15 Monastir | 2021/05/23 08:30 | Jeremy Beale v Yunseong Chung | 4-6,2-6 |