Keiko Ishida defeated Yoshiko Sasano 5-7 6-2 6-4 in the Haibara 10K qualifying round on carpet. The upset overturned the form book — Yoshiko Sasano came in leading the head-to-head 1–0. Keiko Ishida claimed a first win over Yoshiko Sasano in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-09-07 | Kugayama 4 10K | R16 | hard | Yoshiko Sasano | 6-1 3-6 3-1 |