Mari Tanaka defeated Maya Kato 6-3 6-1 in the Tokyo 10K semi-final on carpet. The upset overturned the form book — Maya Kato came in leading the head-to-head 2–1. Mari Tanaka narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-09-20 | Makinohara 25K | R16 | carpet | Maya Kato | 7-6(3) 6-1 |
| 2010-08-23 | Saitama 10K | R32 | hard | Maya Kato | 6-2 3-6 6-4 |
| 2009-08-24 | Saitama 10K | QF | hard | Mari Tanaka | 6-4 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.