Steffi Graf defeated Venus Williams 4-6 6-2 6-4 in the Sydney quarter-final on hard. The upset overturned the form book — Venus Williams came in leading the head-to-head 2–1, defending last year's final. Steffi Graf narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-06-21 | Wimbledon | QF | grass | Steffi Graf | 6-2 3-6 6-4 |
| 1999-03-18 | Key Biscayne | SF | hard | Venus Williams | 6-2 6-4 |
| 1999-02-15 | Hanover | SF | carpet | Venus Williams | 6-3 3-6 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.