Daniel Vacek defeated Marcelo Rios 6-1 6-1 in the New Haven round of 16 on hard. The upset overturned the form book — Marcelo Rios came in leading the head-to-head 4–1, defending last year's round of 16. Daniel Vacek narrowed the head-to-head to 4–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2001-09-24 | Hong Kong | R32 | hard | Marcelo Rios | 6-2 6-1 |
| 2000-03-13 | Indian Wells Masters | R64 | hard | Marcelo Rios | 7-6 6-1 |
| 1998-08-31 | US Open | R128 | hard | Marcelo Rios | 6-4 6-2 6-3 |
| 1998-08-10 | Cincinnati Masters | R32 | hard | Daniel Vacek | 6-3 6-2 |
| 1995-08-21 | Long Island | R32 | hard | Marcelo Rios | 7-5 6-4 |
Averages over each player's completed matches in the selected window (180 vs 200). 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