Angelique Kerber defeated Polona Hercog 6-4 6-2 in the Luxembourg quarter-final on hard. The upset overturned the form book — Polona Hercog came in leading the head-to-head 3–2, defending last year's round of 16. Angelique Kerber narrowed the head-to-head to 3–3.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2019-09-30 | Beijing | R32 | hard | Polona Hercog | 6-4 6-2 |
| 2019-01-14 | Australian Open | R128 | hard | Angelique Kerber | 6-2 6-2 |
| 2016-08-29 | US Open | R128 | hard | Angelique Kerber | 6-0 1-0 RET |
| 2011-02-28 | Monterrey | R32 | hard | Polona Hercog | 6-3 6-3 |
| 2010-05-17 | Warsaw | R32 | clay | Polona Hercog | 6-2 6-3 |
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 (198 vs 200). ATP, WTA & Challenger.