Andrea Petkovic has reached the second round of the Bronx Open with a 6-3, 6-4 victory over fourth seed Shuai Zhang.
The German maintained her perfect record against the Chinese, now 3-0 lifetime against Zhang. Petkovic will face Camila Giorgi for a place in the quarterfinals.
Petkovic seals upset, advances to round two
Both players held serve through the first four games as there was nothing between them. The fifth game would prove to be the turning point of the opening set.
Zhang double-faulted and combined with some powerful returns from Petkovic, the German took a 3-2 lead.
The world number 89 had her serve working, but Zhang broke back only to see Petkovic run off the final three games, serving an ace on set point to take the lead.
The German was quick off the mark in the second set, Zhang with some sloppy play and Petkovic blistering her forehand for a 3-0 double break lead.
As she did in the first set, Zhang came back and this time reeled off four straight games to take a 4-3 advantage.
Her momentum was short-lived as Petkovic got her forehand dialed in again and broke in the ninth game for a 5-4 advantage.
The German was able to serve out the match at the first time of asking and will look to win back-to-back matches for the first time since the French Open when she takes on Giorgi.
"We both like to play aggressive and fast", Petkovic said following the match. "Whoever got in the first strike was on the front foot. I think I did that well in the first set and the beginning of the second.
"She had a few games where she played really well and I became passive and gave her the chance to play aggressive.
"I was a little short with the depth of my ball. I focused on getting the depth back and trying to place the ball closer to the baseline to push her back behind and it worked out really well."