Polona Hercog defeated Su Wei Hsieh 6-1 7-5 in the Sydney qualifying round 2 on hard. The upset overturned the form book — Su Wei Hsieh came in leading the head-to-head 3–1. Polona Hercog narrowed the head-to-head to 3–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2018-12-31 | Auckland | R32 | hard | Su Wei Hsieh | 6-2 6-3 |
| 2018-09-10 | Hiroshima | R32 | hard | Su Wei Hsieh | 4-6 6-1 6-3 |
| 2018-04-09 | Lugano | R32 | clay | Polona Hercog | 7-5 6-0 |
| 2015-09-14 | Tokyo | R32 | hard | Su Wei Hsieh | 6-1 5-7 7-5 |
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 (200 vs 200). ATP, WTA & Challenger.