Kaori Onishi defeated Mari Tanaka 4-6 6-4 6-1 in the Tokyo 10K final on carpet. The upset overturned the form book — Mari Tanaka came in leading the head-to-head 2–0. Kaori Onishi claimed a first win over Mari Tanaka in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-09-13 | Kyoto 10K | R32 | carpet | Mari Tanaka | 6-1 6-4 |
| 2009-06-08 | Tokyo 10K | R32 | hard | Mari Tanaka | 4-6 6-4 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.