BEIJING, China – No.8 seed Kiki Bertens strengthened her shot at a second straight WTA Finals appearance with a dramatic 7-6(6), 2-6, 6-3 win over Samsung Open champion Polona Hercog to reach the China Open quarterfinals.

Bertens, who remains in hot pursuit of a berth at the Shiseido WTA Finals Shenzhen, shook off a second set struggle to defeat the unseeded Hercog in two hours and 18 minutes as night fell on Lotus Court.

The Dutch star is in the midst of another career year after capturing a maiden Premier Mandatory title at the Mutua Madrid Open earlier this season, but has largely been left looking for that level since reaching the Palermo Ladies Open after Wimbledon, falling in the third round of the Dongfeng Motor Wuhan Open to eventual champion Aryna Sabalenka last week.