Ayumi Oka defeated Yuka Higuchi 6-2 6-0 in the Noto 25K q16 on carpet. The result followed the form book — Ayumi Oka came in leading the head-to-head 3–0. Ayumi Oka extended the head-to-head to 4–0.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-08-22 | Saitama 10K | R16 | hard | Ayumi Oka | 7-6(5) 7-5 |
| 2011-06-06 | Tokyo 10K | R16 | hard | Ayumi Oka | 6-4 2-6 6-2 |
| 2011-04-25 | Gifu 50K | Q16 | hard | Ayumi Oka | 7-6(5) 7-5 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.