Stadium: Court 4 Round: 26 Ground: Hardcourt indoor
| ITF M15 Ithaca | 2021/11/03 17:55 | Michael Zheng v Colin Sinclair | 0-6,2-6 |
| ITF M15 Tallahassee | 2021/10/27 14:00 | Colin Sinclair v Ryan Shane | 6-3,3-6,6-7 |
| ITF M15 Ithaca | 2021/10/05 16:00 | Taha Baadi v Colin Sinclair | 7-6,7-5 |
| ITF M25 Budapest | 2021/09/28 10:45 | Pawel Juszczak v Colin Sinclair | 6-2,7-6 |
| UTR Pro Tennis Series Mulheim | 2021/09/25 13:30 | Colin Sinclair v Guy Den Heijer | 2-6,3-5 |
| UTR Pro Tennis Series Mulheim | 2021/09/25 10:00 | Colin Sinclair v Jing L Weng | 6-1,6-4 |
| UTR Pro Tennis Series Mulheim | 2021/09/23 11:00 | Colin Sinclair v Jurriaan Bol | 6-3,6-3 |
| UTR Pro Tennis Series Mulheim | 2021/09/22 14:00 | Colin Sinclair v Christos Keisidis | 6-3,6-1 |
| ITF M15 Ithaca | 2021/11/03 18:35 | John McNally v Vasil Kirkov | 7-6,2-6,1-6 |
| ITF M15 Tallahassee | 2021/10/31 14:00 | Johannes Ingildsen v Vasil Kirkov | 6-4,1-6,2-6 |
| ITF M15 Tallahassee | 2021/10/30 13:55 | Vasil Kirkov v Henry Patten | 4-6,6-3,6-3 |
| ITF M15 Tallahassee | 2021/10/29 13:55 | Ben Shelton v Vasil Kirkov | 6-7,6-2,3-6 |
| ITF M15 Tallahassee | 2021/10/28 15:50 | John McNally v Vasil Kirkov | 4-6,2-6 |
| ITF M15 Tallahassee | 2021/10/27 18:00 | Liam Draxl v Vasil Kirkov | 3-6,3-6 |
| ITF M25 Prague | 2021/10/07 13:00 | Timo Stodder v Vasil Kirkov | 6-2,6-1 |
| ITF M25 Prague | 2021/10/06 07:55 | Vasil Kirkov v Adam Januska | 6-0,6-0 |