Gaston Gaudio defeated Stefan Koubek 6-3 6-1 in the Gstaad quarter-final on clay. The upset overturned the form book — Stefan Koubek came in leading the head-to-head 2–1, defending last year's round of 16. Gaston Gaudio narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2004-10-25 | Basel | R16 | hard | Stefan Koubek | 6-1 1-6 6-3 |
| 2002-07-22 | Kitzbuhel | R16 | clay | Gaston Gaudio | 3-6 6-1 6-0 |
| 2000-02-21 | Mexico City | QF | clay | Stefan Koubek | 7-6(5) 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.