Yvonne Doyle defeated Mareze Joubert 6-4 6-4 in the Frinton 10K qualifying round on grass. The upset overturned the form book — Mareze Joubert came in leading the head-to-head 1–0. Yvonne Doyle claimed a first win over Mareze Joubert in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-07-12 | Frinton 10K | R16 | grass | Mareze Joubert | 6-2 6-2 |