Stadium: Court 3 Round: 14 Ground: Hardcourt outdoor
| Challenger Little Rock | 2021/05/31 15:00 | Stefan Kozlov v Strong Kirchheimer | 6-3,6-2 |
| Challenger Little Rock | 2021/05/30 19:40 | Strong Kirchheimer v Aleksandar Kovacevic | 6-4,6-7,7-6 |
| ITF M25 Pensacola | 2021/05/20 14:25 | Strong Kirchheimer v Nicolas Kicker | 6-4,5-7,2-6 |
| ITF M25 Pensacola | 2021/05/19 18:00 | Strong Kirchheimer v Ricardo Rodriguez-Pace | 6-4,6-3 |
| Challenger Tallahassee | 2021/04/19 16:45 | Alexander Ritschard v Strong Kirchheimer | 6-0,7-6 |
| Challenger Tallahassee | 2021/04/19 00:20 | Strong Kirchheimer v Denis Yevseyev | 6-4,4-6,6-4 |
| 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 |
| Challenger Oeiras | 2021/05/23 11:35 | Nicolas Alvarez v Timofey Skatov | 3-6,2-6 |
| ITF M25 Vic | 2021/05/18 09:50 | Nicolas Alvarez v Maxime Hamou | 6-4,0-6,6-7 |
| ITF M25 Prague | 2021/05/09 13:30 | Nicolas Alvarez v Milos Karol | 3-6,4-6 |
| Challenger Salinas 2 | 2021/04/27 14:30 | Nicolas Alvarez v Tak Khunn Wang | 6-7,4-6 |
| Challenger Salinas 2 | 2021/04/26 18:00 | Nicolas Alvarez v Yusuke Takahashi | 7-6,6-0 |
| Challenger Salinas | 2021/04/19 17:55 | Nicolas Alvarez v Nicolas Jarry | 1-6,1-6 |
| Challenger Santiago | 2021/03/18 16:00 | Nicolas Jarry v Nicolas Alvarez | 6-3,6-4 |
| Challenger Santiago | 2021/03/16 15:15 | Nicolas Alvarez v Pedro Sakamoto | 3-6,6-4,6-3 |