| UTR Pro Tennis Series Cancun | 2021/04/06 17:00 | Nathan Oppenheim v Manuel S Montemayor | 2-6,2-6 |
| UTR Pro Tennis Series California | 2021/05/26 18:24 | Humberto Lopez v Nathan Oppenheim | 6-1,7-5 |
| UTR Pro Tennis Series California | 2021/05/23 16:30 | Nathan Oppenheim v Hiroki Sakagawa | 1-6,1-6 |
| UTR Pro Tennis Series Cancun | 2021/04/10 17:30 | Clemens Graute v Nathan Oppenheim | 6-4,5-7,6-3 |
| UTR Pro Tennis Series Cancun | 2021/04/08 14:30 | Nathan Oppenheim v Jose Antonio Rodriguez Rodriguez | 6-3,6-2 |
| UTR Pro Tennis Series Cancun | 2021/04/07 19:00 | Nathan Oppenheim v Juan A H Serrano | 0-6,0-6 |
| UTR Pro Tennis Series Cancun | 2021/04/06 17:00 | Nathan Oppenheim v Manuel S Montemayor | 2-6,2-6 |
| UTR Pro Tennis Series Cancun | 2021/04/05 16:00 | Nathan Oppenheim v Jean-Baptiste Badon | 4-6,4-6 |
| UTR Pro Tennis Series Manzanillo | 2021/08/02 14:30 | Isaac A Arevalo v Manuel S Montemayor | 4-6,3-2 |
| UTR Pro Tennis Series Cancun | 2021/04/10 16:00 | Manuel S Montemayor v Evan Bynoe | 4-6,3-6 |
| UTR Pro Tennis Series Cancun | 2021/04/09 16:00 | Jean-Baptiste Badon v Manuel S Montemayor | 3-6,6-2,6-3 |
| UTR Pro Tennis Series Cancun | 2021/04/08 16:30 | Juan A H Serrano v Manuel S Montemayor | 6-1,6-4 |
| UTR Pro Tennis Series Cancun | 2021/04/06 17:00 | Nathan Oppenheim v Manuel S Montemayor | 2-6,2-6 |
| UTR Pro Tennis Series Cancun | 2021/04/05 15:30 | Manuel S Montemayor v Jose Antonio Rodriguez Rodriguez | 2-6,6-3,6-3 |