Guillermo Canas defeated Gaston Gaudio 6-4 6-4 in the Acapulco quarter-final on hard. The upset overturned the form book — Gaston Gaudio came in leading the head-to-head 4–3. Guillermo Canas narrowed the head-to-head to 4–4.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2004-07-12 | Stuttgart | F | grass | Guillermo Canas | 5-7 6-2 6-0 1-6 6-3 |
| 2004-05-24 | Roland Garros | R128 | clay | Gaston Gaudio | 6-2 2-6 4-6 6-3 6-2 |
| 2004-03-01 | Acapulco | R16 | hard | Guillermo Canas | 6-4 6-3 |
| 2002-03-11 | Indian Wells Masters | R64 | hard | Gaston Gaudio | 6-4 6-2 |
| 2001-06-25 | Wimbledon | R128 | grass | Guillermo Canas | 1-6 6-1 3-6 6-2 7-5 |
| 2000-04-10 | Estoril | R32 | clay | Gaston Gaudio | 6-3 6-4 |
| 1999-10-04 | Palermo | R32 | clay | Gaston Gaudio | 6-0 6-4 |
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About
Averages over each player's completed matches in the selected window (200 vs 200). ATP, WTA & Challenger.