Guillermo Hormazabal defeated Hermes Gamonal 6-1 6-2 in the Chile F5 qualifying round on clay. The upset overturned the form book — Hermes Gamonal came in leading the head-to-head 2–0. Guillermo Hormazabal claimed a first win over Hermes Gamonal in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-07-17 | Italy F23 | SF | clay | Hermes Gamonal | 7-5 6-4 |
| 2004-08-09 | Chile F1B | R32 | clay | Hermes Gamonal | 6-3 6-7(7) 7-5 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.