Stadium: Court 4 Round: 45 Ground: Clay
| ITF Chile F3 | 2018/11/24 15:00 | Ortiz, Oscar Gabriel v Leiva Biason, Oscar Mattias | 6-2,6-4 |
| ITF Chile F2 | 2018/11/17 16:00 | Leiva Biason, Oscar Mattias v Berne, Mateo | 6-3,3-6,3-6 |
| ITF Chile F1 | 2018/11/12 13:00 | Leiva Biason, Oscar Mattias v Aguilar, Federico Juan | 1-6,3-6 |
| ITF Belgium F7 Qual | 2018/08/05 08:00 | Mertens, Nico v Leiva Biason, Oscar Mattias | 6-1,6-0 |
| ITF Belgium F7 Qual | 2018/08/04 07:30 | Leiva Biason, Oscar Mattias v Velasquez Meza, Javier Alonso | 6-0,6-0 |
| ITF Belgium F6 Qual | 2018/07/28 09:30 | Delmas, Amaury v Leiva Biason, Oscar Mattias | 6-0,6-3 |
| ITF Germany F9 | 2018/07/22 08:00 | Leiva Biason, Oscar Mattias v Dettinger, Moritz | 2-6,1-6 |
| ITF Belgium F4 | 2018/07/14 07:00 | Naser, Javier v Leiva Biason, Oscar Mattias | 6-2,6-0 |
| ITF - M15 Antalya | 2019/02/04 07:00 | Nusdeo, Joao Marcos v Alexandros Skorilas | 3-6,1-6 |
| ITF South Africa F3 Qual | 2018/12/01 07:00 | Nusdeo, Joao Marcos v Thirouin, Jean | 4-6,1-6 |
| Afrique du Sud F2, Qualifications Simples | 2018/11/25 13:00 | Nusdeo, Joao Marcos v Bybel, Nicholas | 4-6,0-6 |
| Afrique du Sud F2, Qualifications Simples | 2018/11/24 07:00 | Nusdeo, Joao Marcos v Kotze, Da-Niel | 6-2,6-0 |
| ITF Brazil F9 | 2018/11/13 16:00 | Nusdeo, Joao Marcos v Luis Britto | 2-6,0-6 |
| ITF Brazil F9 | 2018/11/12 13:35 | Nusdeo, Joao Marcos v Ono, Vinicius | 1-6,2-6 |
| ITF Brazil F9 | 2018/11/11 14:00 | Nusdeo, Joao Marcos v Stefani Figlia, B. | 7-6,3-6,6-2 |
| ITF Brazil F8 | 2018/11/05 21:20 | Nusdeo, Joao Marcos v Marques Da Silva, Rafael | 3-6,3-6 |