Stadium: Quadra 3 Round: 27 Ground: Clay
| Challenger Campinas MD | 2021/11/17 17:00 | Cid Subervi/Sakamoto v Cerundolo/Ugo Carabelli | 6-1,6-2 |
| Challenger Campinas MD | 2021/11/17 21:30 | Klier Junior/P De Almeida v Luz/Martinez | 6-3,3-6,10-4 |
| Challenger Montevideo MD | 2021/11/11 01:05 | Cerundolo/Cuevas v Klier Junior/P De Almeida | 6-3,6-2 |
| ITF M25 Kiseljak MD | 2021/05/29 13:30 | Reis da Silva/Sels v Klier Junior/P De Almeida | 4-6,6-4,10-4 |
| ITF M25 Kiseljak MD | 2021/05/28 17:00 | Basic/Fatic v Klier Junior/P De Almeida | 7-5,3-6,8-10 |
| ITF M25 Kiseljak MD | 2021/05/27 13:40 | Onclin/Riedi v Klier Junior/P De Almeida | 2-6,7-6,13-15 |
| ITF M25 Kiseljak MD | 2021/05/25 15:35 | Makk/Palovic v Klier Junior/P De Almeida | 0-6,1-6 |