Tanja Ostertag defeated Ksenia Kirillova 6-4 7-6 in the Lenzerheide 10K round of 16 on clay. The upset overturned the form book — Ksenia Kirillova came in leading the head-to-head 1–0. Tanja Ostertag claimed a first win over Ksenia Kirillova in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-04-06 | Antalya-Belek 10K | R32 | hard | Ksenia Kirillova | 6-4 6-2 |