Stadium: Hamilton Family Stadium Round: 45 Ground: Hardcourt indoor
| Challenger Newport Beach | 2018/01/23 21:25 | Taylor Fritz v Guillermo Olaso | 6-3,6-4 |
| Challenger Newport Beach Qual | 2018/01/22 18:00 | Guillermo Olaso v JC Aragone | 6-3,2-6,7-6 |
| Challenger Newport Beach Qual | 2018/01/21 20:25 | Brayden Schnur v Guillermo Olaso | 6-4,4-6,4-6 |
| Challenger Newport Beach Qual | 2018/01/20 22:05 | Ante Pavic v Guillermo Olaso | 3-6,3-6 |
| Challenger Bangkok | 2018/01/09 03:00 | Guillermo Olaso v Pedro Martinez | 4-6,4-6 |
| ITF USA F1 | 2018/01/04 20:40 | Guillermo Olaso v Christopher Eubanks | 1-6,3-6 |
| ITF USA F1 | 2018/01/02 19:35 | Brandon Nakashima v Guillermo Olaso | 2-6,6-7 |
| ITF Tunisia F32 | 2017/10/29 08:30 | Guillermo Olaso v Alexandre Muller | 6-4,3-6,3-6 |