Dutch top seed Kiki Bertens beat Croatia's Donna Vekic for the third consecutive time this year with a 7-6(5) 6-2 victory in their round robin match at the WTA Elite Trophy in Zhuhai on Tuesday.
Bertens, playing in her seventh tournament since her U.S. Open third round exit, was pushed to the limit in an absorbing opening set that lasted an hour and 20 minutes, with a number of games going to deuce and plenty of break points available.
There were 15 break points in the match, with Bertens converting four and Vekic winning two.
"The first set was really tight, so it was just a few points here and there," Bertens told reporters. "I was just trying to push myself all the time.
"It was tough... mentally but also physically. We were both struggling a little bit. But from 5-4 down I played two really good points."