Mari Tanaka defeated Ayumi Oka 2-6 6-4 6-2 in the Tokyo 10K qualifying round on hard. Mari Tanaka extended the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-09-14 | Kyoto 10K | QF | carpet | Ayumi Oka | 6-2 6-4 |
| 2005-08-29 | Saitama 10K | R16 | hard | Mari Tanaka | 7-6(4) 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.