Karolina Wlodarczak defeated Marcella Koek 7-5 6-4 in the Lenzerheide 10K round of 32 on clay. The upset overturned the form book — Marcella Koek came in leading the head-to-head 1–0, but Karolina Wlodarczak had been the form player, winning 2 of their last 5 on clay. Karolina Wlodarczak claimed a first win over Marcella Koek in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-05-02 | Wiesbaden 10K | SF | clay | Marcella Koek | 7-5 7-6(5) |