Seiko Okamoto defeated Sachie Umehara 5-4 4-1 4-5 1-4 4-1 in the Kofu Open qualifying round on carpet. The upset overturned the form book — Sachie Umehara came in leading the head-to-head 2–0. Seiko Okamoto claimed a first win over Sachie Umehara in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2001-11-19 | Kofu 10K | SF | clay | Sachie Umehara | 6-3 4-6 6-3 |
| 1997-09-08 | Kugayama 3 10K | R16 | hard | Sachie Umehara | 7-6 3-6 6-3 |