Juan Albert Viloca Puig defeated Nicolas Kiefer 6-4 6-3 in the Gstaad quarter-final on clay. The upset overturned the form book — Nicolas Kiefer came in leading the head-to-head 1–0. Juan Albert Viloca Puig claimed a first win over Nicolas Kiefer in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-07-06 | Gstaad | R32 | clay | Nicolas Kiefer | 0-6 7-5 7-6(8) |
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 (88 vs 200). ATP, WTA & Challenger.