Mariano Zabaleta defeated Stefan Koubek 3-6 6-2 6-4 in the St. Petersburg round of 32 on carpet. The upset overturned the form book — Stefan Koubek came in leading the head-to-head 2–1, defending last year's quarter-final. Mariano Zabaleta narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-09-11 | Bucharest | R32 | clay | Stefan Koubek | 4-6 6-4 6-3 |
| 2003-01-06 | Auckland | QF | hard | Mariano Zabaleta | 6-2 6-1 |
| 1998-09-14 | Bournemouth | R32 | clay | Stefan Koubek | 6-1 5-7 7-6(6) |
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.