Stadium: Indoor Court 3 Round: 25 Ground: Clay
| Challenger Poznan Qual | 2018/06/04 13:30 | Jeremy Jahn v Guillermo Olaso | 6-7,6-1,6-2 |
| Challenger Poznan Qual | 2018/06/04 08:00 | Ronald Slobodchikov v Guillermo Olaso | 4-6,6-3,1-6 |
| Challenger Poznan Qual | 2018/06/03 09:25 | Juan Pablo Ficovich v Guillermo Olaso | 4-6,2-6 |
| Challenger Busan Qual | 2018/05/14 02:00 | Rubin Statham v Guillermo Olaso | 6-4,6-2 |
| Challenger Busan Qual | 2018/05/13 02:00 | Thomas Fancutt v Guillermo Olaso | 1-6,5-7 |
| Challenger Busan Qual | 2018/05/12 01:00 | Jae Hwan Kim v Guillermo Olaso | 0-6,5-7 |
| Challenger Glasgow | 2018/05/04 09:30 | Lukas Lacko v Guillermo Olaso | 6-2,6-3 |
| Challenger Glasgow | 2018/05/02 13:50 | Guillermo Olaso v Lloyd Glasspool | 6-4,6-3 |
| ITF France F10 Qual | 2018/06/17 14:25 | Allan Deschamps v Eduard Guell | 6-7,3-6 |
| ITF France F10 Qual | 2018/06/16 16:40 | Enzo Le Seguillon v Eduard Guell | 2-6,3-6 |
| ITF Spain F14 Qual | 2018/06/03 08:30 | Felipe Meligeni Rodrigues Alves v Eduard Guell | 6-2,6-3 |