Boy Westerhof defeated Bas Van Der Valk 6-7 6-1 6-3 in the Netherlands F1 round of 16 on clay. The upset overturned the form book — Bas Van Der Valk came in leading the head-to-head 1–0. Boy Westerhof claimed a first win over Bas Van Der Valk in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-08-28 | Netherlands F5 | R32 | clay | Bas Van Der Valk | 6-2 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.