Stadium: Court 2 Round: 26 Ground: Hardcourt outdoor
| Challenger Rio De Janeiro | 2021/12/13 18:00 | Pedja Krstin v Luciano Darderi | 2-6,6-7 |
| Challenger Florianopolis | 2021/12/07 13:00 | Pedja Krstin v Hernan Casanova | 7-5,1-6,2-6 |
| Challenger Champaign | 2021/11/18 17:00 | Pedja Krstin v Ben Shelton | 6-4,0-6,1-6 |
| Challenger Champaign | 2021/11/16 22:10 | Pedja Krstin v Arjun Kadhe | 7-5,7-5 |
| Challenger Guayaquil | 2021/11/02 17:10 | Hugo Dellien v Pedja Krstin | 6-4,6-2 |
| Challenger Lima | 2021/10/26 23:00 | Juan Pablo Varillas v Pedja Krstin | 6-3,6-1 |
| Challenger Bogota | 2021/10/19 16:30 | Goncalo Oliveira v Pedja Krstin | 3-6,6-3,6-2 |
| Challenger Barcelona | 2021/10/05 09:45 | Pedja Krstin v Nicola Kuhn | 4-6,4-6 |
| US Open | 2021/08/30 19:10 | Grigor Dimitrov v Sam Riffice | 6-1,7-6,6-3 |
| Challenger Lexington | 2021/07/25 20:30 | Stefan Kozlov v Sam Riffice | 6-2,6-3 |
| Challenger Cary | 2021/07/22 18:00 | Sam Riffice v Prajnesh Gunneswaran | 2-6,4-6 |
| Challenger Cary | 2021/07/20 15:00 | Sam Riffice v Tatsuma Ito | 6-7,6-4,7-5 |
| ITF M25 Tulsa | 2021/06/19 14:00 | Genaro Alberto Olivieri v Sam Riffice | 7-6,7-6 |
| ITF M25 Tulsa | 2021/06/18 14:00 | Gage Brymer v Sam Riffice | 0-6,6-7 |
| ITF M25 Tulsa | 2021/06/17 14:00 | Sam Riffice v Jason Kubler | 6-1,6-4 |
| ITF M25 Tulsa | 2021/06/16 14:00 | Nathan Ponwith v Sam Riffice | 5-7,4-6 |