| ITF M15 Cancun | 10/11 17:00 | 44 | Luis Britto v Leiva Biason, Oscar Mattias | 6-1,6-3 | |
| ITF M15 Cancun | 10/03 19:45 | 44 | Leiva Biason, Oscar Mattias v Telles, Leonardo | 3-6,2-6 | |
| ITF M15 Cancun | 09/26 17:30 | 44 | Leiva Biason, Oscar Mattias v Gabriel Roveri Sidney | 1-6,2-6 | |
| ITF M15 Cancun | 09/19 14:00 | 44 | Moceanu, Nikolas v Leiva Biason, Oscar Mattias | 6-1,6-3 | |
| ITF M25 Medellin | 09/12 15:00 | 44 | Nicolas Buitrago v Leiva Biason, Oscar Mattias | 6-0,6-1 | |
| ITF M15 Ibague | 09/05 15:00 | 44 | Escobar, Felipe v Leiva Biason, Oscar Mattias | 6-2,6-1 | |
| ITF M25 Lima | 02/09 15:00 | 44 | Leiva Biason, Oscar Mattias v Bautista Vilicich | 2-6,7-6,2-10 | |
| ITF M25 Lima | 02/03 15:00 | 44 | Miljan Zekic v Leiva Biason, Oscar Mattias | 6-2,6-0 | |
| ITF M25 Lima | 02/02 18:00 | 44 | Leiva Biason, Oscar Mattias v Riquelme Coppari, Agustin | 6-2,2-6,10-6 | |
| ITF M15 Cancun | 12/08 14:00 | 44 | Leiva Biason, Oscar Mattias v Gonzalez, Javier (Chl) | 4-6,1-6 | |
| ITF M15 Cancun | 12/01 19:00 | 44 | Leiva Biason, Oscar Mattias v Benjamin, Jordan | 3-6,1-6 | |
| ITF - M15 Santiago | 09/30 14:00 | 54 | Besada, Santiago v Leiva Biason, Oscar Mattias | 6-4,6-4 | |
| Buenos Aires, Singles Qualifying M-ITF-ARG-22A | 09/15 17:00 | 44 | Mariano Navone v Leiva Biason, Oscar Mattias | 6-1,6-1 | |
| ITF M25 Lima | 07/15 15:00 | 54 | Daniel Antonio Nunez v Leiva Biason, Oscar Mattias | 6-4,6-3 | |
| ITF M15 Lima | 07/09 14:00 | 54 | Leiva Biason, Oscar Mattias v Agustin Maria Gascia | 4-6,3-6 | |
| Curitiba, Singles M-ITF-BRA-04A | 06/24 18:30 | 54 | Leiva Biason, Oscar Mattias v Azevedo Pereira E Oliveira, Bernardo | 4-6,6-4,4-10 | |
| Sao Jose Do Rio Preto, Singles M-ITF-BRA-03A | 06/17 16:00 | 54 | Leiva Biason, Oscar Mattias v Riquelme Coppari, Agustin | 3-6,5-7 | |
| Bucaramanga, Singles M-ITF-COL-01A | 04/22 20:30 | 45 | Leiva Biason, Oscar Mattias v Nusdeo, Joao Marcos | 2-6,6-7 | |
| ITF M15 Guayaquil | 04/15 15:00 | 45 | Leiva Biason, Oscar Mattias v Nusdeo, Joao Marcos | 4-6,2-6 | |
| ITF Chile F3 | 11/24 15:00 | 44 | Ortiz, Oscar Gabriel v Leiva Biason, Oscar Mattias | 6-2,6-4 | |
| ITF Chile F2 | 11/17 16:00 | 44 | Leiva Biason, Oscar Mattias v Berne, Mateo | 6-3,3-6,3-6 | |
| ITF Chile F1 | 11/12 13:00 | 44 | Leiva Biason, Oscar Mattias v Aguilar, Federico Juan | 1-6,3-6 | |
| ITF Belgium F7 Qual | 08/05 08:00 | 62 | Mertens, Nico v Leiva Biason, Oscar Mattias | 6-1,6-0 | |
| ITF Belgium F7 Qual | 08/04 07:30 | 62 | Leiva Biason, Oscar Mattias v Velasquez Meza, Javier Alonso | 6-0,6-0 | |
| ITF Belgium F6 Qual | 07/28 09:30 | 44 | Delmas, Amaury v Leiva Biason, Oscar Mattias | 6-0,6-3 | |
| ITF Germany F9 | 07/22 08:00 | 62 | Leiva Biason, Oscar Mattias v Dettinger, Moritz | 2-6,1-6 | |
| ITF Belgium F4 | 07/14 07:00 | 44 | Naser, Javier v Leiva Biason, Oscar Mattias | 6-2,6-0 | |
| ITF Germany F7 | 07/09 08:00 | 44 | Andres Urrea v Leiva Biason, Oscar Mattias | 7-6,6-2 | |
| ITF Belgium F2 Qual | 06/24 14:50 | 44 | Leiva Biason, Oscar Mattias v Paul Valsecchi | 2-6,1-6 | |
| ITF Belgium F2 Qual | 06/23 13:20 | 44 | Leiva Biason, Oscar Mattias v Zekri, Yannis | 6-1,6-0 |