Stadium: Court 3 Round: 25 Ground: Hardcourt outdoor
| Challenger Sao Paulo | 2021/11/30 12:30 | Pedro Sakamoto v Soares Klier, Gilbert | 2-6,7-5,7-5 |
| Challenger Brasilia | 2021/11/24 13:00 | Pedro Cachin v Soares Klier, Gilbert | 3-6,6-3,7-6 |
| Challenger Brasilia | 2021/11/23 13:00 | Soares Klier, Gilbert v Gomez, Alejandro | 6-3,7-6 |
| Challenger Campinas | 2021/11/16 14:55 | Francisco Cerundolo v Soares Klier, Gilbert | 6-3,6-0 |
| Montevideo, Uruguay | 2021/11/07 15:00 | Soares Klier, Gilbert v Dario Acosta | 6-3,7-5 |
| ITF M25 Rio do Sul | 2021/10/21 14:50 | Soares Klier, Gilbert v Pedro Boscardin Dias | 6-2,3-6,2-6 |
| ITF M25 Rio do Sul | 2021/10/20 14:45 | Soares Klier, Gilbert v Mateo Barreiros Reyes | 3-6,6-1,6-2 |
| ITF M25 Lima | 2021/10/17 15:00 | Soares Klier, Gilbert v Daniel Dutra Da Silva | 7-6,6-3 |