Lilia Osterloh defeated Jane Chi 3-6 6-4 6-4 in the Oklahoma quarter-final on hard. The upset overturned the form book — Jane Chi came in leading the head-to-head 1–0. Lilia Osterloh claimed a first win over Jane Chi in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-09-28 | Santa Clara 75K | R32 | hard | Jane Chi | 6-4 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.