Stadium: Stadium Round: 25 Ground: Hardcourt outdoor
| ATP Newport | 2021/07/11 20:10 | Ulises Blanch v Thai-Son Kwiatkowski | 2-6,6-2,7-6 |
| Wimbledon | 2021/06/22 10:00 | Thai-Son Kwiatkowski v Antoine Hoang | 6-3,3-6,4-6 |
| Challenger Orlando | 2021/06/09 16:00 | Thai-Son Kwiatkowski v Ulises Blanch | 6-7,6-3,2-6 |
| Challenger Orlando | 2021/06/08 16:10 | Ernesto Escobedo v Thai-Son Kwiatkowski | 4-6,6-7 |
| Challenger Little Rock | 2021/06/04 21:45 | Jack Sock v Thai-Son Kwiatkowski | 6-7,7-6,6-4 |
| Challenger Little Rock | 2021/06/03 16:00 | Alexander Ritschard v Thai-Son Kwiatkowski | 7-5,3-6,2-6 |
| Challenger Little Rock | 2021/06/02 20:40 | Stefan Kozlov v Thai-Son Kwiatkowski | 2-6,1-6 |
| French Open | 2021/05/26 12:20 | Francisco Cerundolo v Thai-Son Kwiatkowski | 6-7,6-4,7-6 |
| Challenger Braunschweig | 2021/07/04 14:25 | Prajnesh Gunneswaran v Benjamin Hassan | 5-7,4-6 |
| Challenger Porto | 2021/07/01 10:00 | Steven Diez v Prajnesh Gunneswaran | 6-3,1-6,6-4 |
| Challenger Porto | 2021/06/29 16:10 | Mathias Bourgue v Prajnesh Gunneswaran | 2-6,6-3,1-6 |
| Wimbledon | 2021/06/22 13:30 | Arthur Fery v Prajnesh Gunneswaran | 6-1,7-6 |
| French Open | 2021/05/25 08:30 | Oscar Otte v Prajnesh Gunneswaran | 6-2,6-2 |
| ATP Geneva | 2021/05/16 08:30 | Prajnesh Gunneswaran v Mackenzie McDonald | 3-6,6-3,3-6 |
| Challenger Heilbronn | 2021/05/10 15:40 | Alessandro Giannessi v Prajnesh Gunneswaran | 7-6,6-1 |
| ATP Munich | 2021/04/24 12:15 | Prajnesh Gunneswaran v Dennis Novak | 4-6,6-3,5-7 |