Stadium: Stadium Court Round: 14 Ground: Clay
| Challenger Cleveland | 2021/03/15 14:00 | Strong Kirchheimer v Alexis Galarneau | 6-7,6-1,4-6 |
| Challenger Cleveland | 2021/03/14 19:00 | Strong Kirchheimer v Kyle Kang | 6-4,6-1 |
| ITF M25 Naples | 2021/02/25 15:00 | Mitchell Krueger v Strong Kirchheimer | 6-4,6-4 |
| ITF M25 Naples | 2021/02/24 16:35 | Fletcher Scott v Strong Kirchheimer | 4-6,2-6 |
| ITF M25 Naples | 2021/02/18 15:00 | Alejandro Gonzalez v Strong Kirchheimer | 3-6,7-6,7-6 |
| ITF M25 Naples | 2021/02/17 16:45 | Strong Kirchheimer v JC Aragone | 3-6,6-2,6-1 |
| UTR Pro Tennis Series - Florida | 2021/01/24 14:00 | Strong Kirchheimer v Cristian C. Rodriguez Sanchez | 7-6,3-6,6-4 |
| UTR Pro Tennis Series - Florida | 2021/01/23 17:00 | Matija Pecotic v Strong Kirchheimer | 5-7,2-5 |
| Challenger Oeiras - kvalifikace | 2021/04/04 13:40 | Evan Furness v Denis Yevseyev | 7-6,5-7,6-3 |
| Challenger Oeiras | 2021/03/30 11:25 | Goncalo Oliveira v Denis Yevseyev | 6-1,6-2 |
| Challenger Oeiras | 2021/03/29 14:55 | Pedro Araujo v Denis Yevseyev | 2-6,2-6 |
| Challenger Oeiras | 2021/03/28 10:00 | Sergio Martos Gornes v Denis Yevseyev | 3-6,3-6 |
| Challenger Petrohrad | 2021/03/10 08:30 | Denis Yevseyev v Dmitry Popko | 4-6,6-2,4-6 |
| Challenger Petrohrad | 2021/03/09 09:55 | Denis Yevseyev v Vaja Uzakov | 6-0,6-0 |
| Challenger Nur-Sultan | 2021/03/01 10:55 | Denis Yevseyev v Tatsuma Ito | 4-6,6-2,3-6 |
| Challenger Nur-Sultan | 2021/02/23 06:00 | Denis Istomin v Denis Yevseyev | 6-7,6-3,6-3 |