Ayumi Oka defeated Sakiko Shimizu 2-6 6-4 6-1 in the Tokyo 10K qualifying round on carpet. The upset overturned the form book — Sakiko Shimizu came in leading the head-to-head 1–0. Ayumi Oka claimed a first win over Sakiko Shimizu in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-08-23 | Saitama 10K | R32 | hard | Sakiko Shimizu | 7-5 6-3 |