Shizu Katsumi defeated Natsumi Hamamura 6-1 6-3 in the Tokyo 10K round of 16 on hard. The upset overturned the form book — Natsumi Hamamura came in leading the head-to-head 1–0. Shizu Katsumi claimed a first win over Natsumi Hamamura in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-09-11 | Hiroshima 10K | R32 | carpet | Natsumi Hamamura | 6-2 6-1 |