Sakiko Shimizu defeated Ai Koga 6-0 6-2 in the Hamanako 25K q32 on carpet. The upset overturned the form book — Ai Koga came in leading the head-to-head 1–0. Sakiko Shimizu claimed a first win over Ai Koga in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2008-06-09 | Tokyo 10K | R16 | hard | Ai Koga | 3-6 6-4 6-1 |