Ayumi Oka defeated Mari Inoue 7-5 6-1 in the Makinohara 25K round of 32 on carpet. The upset overturned the form book — Mari Inoue came in leading the head-to-head 1–0. Ayumi Oka claimed a first win over Mari Inoue in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-06-01 | Komoro 25K | R16 | clay | Mari Inoue | 6-4 6-0 |