Seiko Okamoto defeated Remi Tezuka 6-4 6-4 in the Ibaraki 2 10K quarter-final on hard. The upset overturned the form book — Remi Tezuka came in leading the head-to-head 2–1. Seiko Okamoto narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-03-22 | Kofu 10K | R32 | hard | Remi Tezuka | 6-3 6-4 |
| 2008-04-21 | Incheon 25K | R32 | hard | Seiko Okamoto | 6-3 6-4 |
| 2000-06-26 | Lachine 10K | R16 | clay | Remi Tezuka | 6-4 6-3 |