Mari Inoue defeated Kazusa Ito 6-3 3-6 6-4 in the Niigata 10K round of 32 on carpet. The upset overturned the form book — Kazusa Ito came in leading the head-to-head 3–1. Mari Inoue narrowed the head-to-head to 3–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-06-06 | Tokyo 10K | R32 | hard | Mari Inoue | 6-3 6-3 |
| 2010-09-13 | Kyoto 10K | R16 | carpet | Kazusa Ito | 6-1 6-2 |
| 2010-04-19 | Mie 10K | R32 | carpet | Kazusa Ito | 6-3 6-1 |
| 2006-08-14 | Tokyo 2 10K | R32 | hard | Kazusa Ito | 6-4 6-4 |