Kiki Bertens defeated Caroline Wozniacki 6-2 6-2 in the Madrid round of 16 on clay. The upset overturned the form book — Caroline Wozniacki came in leading the head-to-head 3–1, defending last year's round of 32. Kiki Bertens narrowed the head-to-head to 3–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2018-08-13 | Cincinnati | R32 | hard | Kiki Bertens | 6-4 0-0 RET |
| 2018-01-15 | Australian Open | R32 | hard | Caroline Wozniacki | 6-4 6-3 |
| 2017-02-13 | Doha | R32 | hard | Caroline Wozniacki | 6-2 6-3 |
| 2012-08-06 | Montreal | R32 | hard | Caroline Wozniacki | 7-5 6-1 |
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About
Averages over each player's completed matches in the selected window (179 vs 135). ATP, WTA & Challenger.
Performance in the biggest moments — break points, deciding sets and tiebreaks (0–100, higher is better). About