Mari Inoue defeated Maya Kato 3-6 6-3 6-3 in the Gunma 25K round of 32 on carpet. The upset overturned the form book — Maya Kato came in leading the head-to-head 2–0. Mari Inoue claimed a first win over Maya Kato in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-08-22 | Saitama 10K | R32 | hard | Maya Kato | 3-6 6-3 6-0 |
| 2007-08-13 | Tokyo 10K | R16 | carpet | Maya Kato | 6-4 6-1 |