Chiaki Okadaue defeated Maya Kato 6-4 4-6 6-2 in the Nagano 25K round of 16 on carpet. The upset overturned the form book — Maya Kato came in leading the head-to-head 1–0. Chiaki Okadaue claimed a first win over Maya Kato in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-06-20 | Pattaya 10K | R32 | hard | Maya Kato | 6-4 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.