Steffi Graf defeated Martina Hingis 4-6 7-5 6-2 in the Roland Garros final on clay. The upset overturned the form book — Martina Hingis came in defending last year's semi-final. Steffi Graf extended the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-02-02 | Tokyo | QF | hard | Martina Hingis | 3-6 6-2 6-4 |
| 1998-11-09 | Philadelphia | QF | carpet | Steffi Graf | 6-2 4-6 6-0 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.