Guillermo Olaso defeated Guillermo Alcorta Olarra 3-6 6-1 6-4 in the Spain F40 round of 16 on hard. Guillermo Olaso extended the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-07-13 | France F12 | QF | clay | Guillermo Olaso | 7-6(4) 6-1 |
| 2008-11-03 | Spain F42 | R16 | hard | Guillermo Alcorta Olarra | 7-5 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.