Top seed Karolina Pliskova was rescued by the rain at the Zhengzhou Open as Polona Hercog's fightback was brought to a halt.
Pliskova started brightly to take the first set 6-3 but the world number two was serving to stay in the second at 5-2 down when the weather intervened, as it had several times during the day.
The duo will resume on Thursday at the WTA Premier event to settle who will make it through to the last eight.
Sofia Kenin awaits the winner after the sixth seed defeated Alize Cornet 6-4 6-2.
Petra Martic, seeded seventh, also progressed but had to battle back from a set down to overcome Fiona Ferro 3-6 6-1 6-2.
There was one seed who suffered a loss, though, with Caroline Garcia beaten 7-5 6-2 at the hands of Kristina Mladenovic.