Stadium: C Round: 54 Ground: Hardcourt indoor
| Challenger San Francisco Qual | 2018/02/04 21:00 | Guillermo Olaso v Jack Molloy | 7-5,6-2 |
| Challenger San Francisco Qual | 2018/02/03 21:55 | Guillermo Olaso v Jacob Brumm | 6-3,6-1 |
| Challenger Dallas Qual | 2018/01/29 18:15 | Evgeny Karlovskiy v Guillermo Olaso | 6-7,6-1,7-6 |
| Challenger Dallas Qual | 2018/01/28 16:00 | Guillermo Olaso v Patricio Heras | 6-0,6-4 |
| Challenger Dallas Qual | 2018/01/27 17:20 | Arnau Dachs v Guillermo Olaso | 3-6,4-6 |
| 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 San Francisco Qual | 2018/02/04 22:20 | Rrezart Cungu v Karue Sell | 3-6,1-6 |
| Challenger San Francisco Qual | 2018/02/03 23:30 | Francesco Ferrari v Karue Sell | 1-6,7-6,3-6 |
| ITF USA F2 | 2018/01/11 20:35 | Daniel Cukierman v Karue Sell | 7-6,6-1 |
| ITF USA F2 | 2018/01/10 21:35 | Yann Marti v Karue Sell | 6-2,4-6,2-6 |
| ITF USA F1 | 2018/01/07 19:00 | Christopher Eubanks v Karue Sell | 7-6,2-6,2-6 |
| ITF USA F1 | 2018/01/06 21:00 | Karue Sell v Jan Satral | 6-4,6-4 |
| ITF USA F1 | 2018/01/05 18:00 | Karue Sell v Alex Rybakov | 6-4,6-3 |
| ITF USA F1 | 2018/01/04 18:00 | Karue Sell v Ulises Blanch | 7-6,6-3 |