Santiago Ventura defeated Daniel Koellerer 6-4 6-2 in the Buenos Aires round of 32 on clay. The upset overturned the form book — Daniel Koellerer came in leading the head-to-head 2–0. Santiago Ventura claimed a first win over Daniel Koellerer in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-02-25 | Acapulco | Q16 | hard | Daniel Koellerer | 6-4 1-0 |
| 2003-05-05 | Italy F6 | R16 | clay | Daniel Koellerer | 7-6(5) 6-2 |
Averages over each player's completed matches in the selected window (13 vs 12). ATP, WTA & Challenger.
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About