Maya Kato defeated Mari Tanaka 6-2 3-6 6-4 in the Saitama 10K round of 32 on hard. The upset overturned the form book — Mari Tanaka came in leading the head-to-head 2–1. Maya Kato 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 |
| 2009-08-24 | Saitama 10K | QF | hard | Mari Tanaka | 6-4 6-3 |
| 2007-08-13 | Tokyo 10K | SF | carpet | Mari Tanaka | 6-3 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.