Round: 26 Ground: Clay
| Spain F30, Singles | 2017/09/20 08:30 | Eriksson, Markus v Colas Sanchez, Alberto | 4-6,6-4,5-7 |
| ITF Spain F25 | 2017/08/17 11:00 | Colas Sanchez, Alberto v Marcelo Zormann | 4-6,4-6 |
| ITF Spain F25 | 2017/08/16 13:00 | Fornell-Mestres, Marc v Colas Sanchez, Alberto | 1-6,0-6 |
| ITF Spain F25 | 2017/08/15 16:25 | Colas Sanchez, Alberto v Sebaoun, Leo Julien | 6-1,6-2 |
| ITF Spain F15 | 2017/05/20 07:00 | Colas Sanchez, Alberto v Ayala Hernandez, Antonio Javier | 3-6,3-6 |
| ITF Spain F21 Qual | 2016/07/10 08:00 | Yamada, Kento v Colas Sanchez, Alberto | 6-3,6-2 |
| ITF Spain F21 Qual | 2016/07/09 10:00 | Colas Sanchez, Alberto v Monsonis Uso, Jose Vicent | 6-3,6-4 |
| Spain F30, Singles | 2017/09/19 10:25 | Sorni Chavarria, Quim v Olaso, Guillermo | 3-6,1-6 |
| ITF Spain F30 Qual | 2017/09/18 10:20 | Olaso, Guillermo v Butler, Harry | 6-1,6-2 |
| ITF Spain F30 Qual | 2017/09/17 12:30 | Olaso, Guillermo v Moura, Hugo | 6-1,6-0 |
| Challenger Alphen Qual | 2017/09/03 12:30 | Cagnina, Julien v Olaso, Guillermo | 3-6,6-1,6-3 |
| Challenger Alphen Qual | 2017/09/03 09:00 | Bednarek, Tomasz v Olaso, Guillermo | 0-6,0-6 |
| ITF Turkey F27 | 2017/07/30 08:00 | Cuevas, Martin v Olaso, Guillermo | 4-6,6-3,4-6 |
| ITF Turkey F27 | 2017/07/28 08:00 | Olaso, Guillermo v Carli, Christian | 6-2,6-2 |
| ITF Turkey F27 | 2017/07/27 07:00 | Olaso, Guillermo v Stergiou, Ioannis | 6-3,6-2 |