Stadium: Estadio Central Round: 25 Ground: Clay
| Santo Domingo, Dominican Republic | 2019/10/08 17:00 | Juan Pablo Ficovich v Clezar, Guilherme | 4-6,3-6 |
| Challenger Campinas | 2019/10/02 19:30 | Hugo Dellien v Clezar, Guilherme | 6-3,6-4 |
| Challenger Campinas | 2019/09/30 13:00 | Jordan Correia Passos Do Carmo v Clezar, Guilherme | 1-6,0-6 |
| Challenger - Buenos Aires | 2019/09/23 20:40 | Clezar, Guilherme v Hernan Casanova | 1-6,3-6 |
| Challenger Banja Luka | 2019/09/12 12:30 | Clezar, Guilherme v Tallon Griekspoor | 4-6,3-6 |
| Challenger Banja Luka | 2019/09/11 12:15 | Dutra Silva, Rogerio v Clezar, Guilherme | 3-6,1-6 |
| Challenger Banja Luka | 2019/09/10 08:00 | Jelle Sels v Clezar, Guilherme | 2-6,3-6 |
| La Marsa, Singles M-ITF-TUN-37A | 2019/09/07 09:30 | Clezar, Guilherme v Louis Wessels | 6-1,3-6,3-6 |
| Challenger Campinas | 2019/10/01 20:10 | Camilo Ugo Carabelli v Mayer, Leonardo | 6-7,4-6 |
| Challenger - Buenos Aires | 2019/09/28 15:20 | Facundo Bagnis v Mayer, Leonardo | 6-2,3-6,6-3 |
| Challenger - Buenos Aires | 2019/09/27 22:25 | Mayer, Leonardo v Juan Pablo Ficovich | 6-1,6-7,7-6 |
| Challenger - Buenos Aires | 2019/09/26 21:30 | Mayer, Leonardo v Facundo Diaz Acosta | 7-6,6-3 |
| Challenger - Buenos Aires | 2019/09/25 20:30 | Mayer, Leonardo v Federico Zeballos | 7-5,6-1 |
| US Open, New York, USA | 2019/08/27 22:00 | Antoine Hoang v Mayer, Leonardo | 3-6,6-2,6-7,6-1,6-3 |
| Kitzbuhel, Austria | 2019/07/30 09:00 | Andujar, Pablo v Mayer, Leonardo | 3-6,6-3,6-2 |
| Hamburg, Germany | 2019/07/22 16:30 | Mayer, Leonardo v Rudolf Molleker | 6-7,4-6 |