Reigning China Open champion Victoria Azarenka crashed out in the first round on Monday as the second seed faced stiff resistance from former finallist Andrea Petkovic.
The Belarusian world number two rarely showed glimpses of the form which helped her claim the title last year, at times appearing sluggish as she committed a staggering 15 double faults in the 6-4, 2-6, 6-4 loss.
It is the second early exit in a row for the 24-year-old, who complained of feeling ill when she was defeated by Venus Williams in the second round of the Pan Pacific Open last week.
Azarenka appeared agitated in the opening set in Beijing’s National Tennis Centre, even before German Petkovic broke her serve following a string of double faults.
China’s Zhang Shuai continued her sizzling form, defeating compatriot Peng Shuai 6-3, 6-3 to set up a second-round match against tenth seed Roberta Vinci.
Wildcard Zhang won her first WTA title in Guangzhou earlier this month.
The 24-year-old recruited her own coach in July, following Chinese star Li Na’s example in leaving the tightly controlled state sports system, raising hopes that she can emulate the success of the 2011 French Open winner.
It was a successful day for three Serbians. Eighth seed Jelana Jankovic needed three sets to overcome Russian Anastasia Pavlyuchenkova 1-6, 6-4, 6-0. Ana Ivanovic claimed victory over Italian Flavia Pennetta 7-6 (11/9), 6-1.
Bojana Jovanovski rounded off a Serbian hat-trick, beating Romanian Sorana Cirstea 6-3, 6-2.
The men’s tournament got under way, but it was heartbreak for the home crowd after China’s top-ranked player fell at the first hurdle.
Zhang Ze was knocked out by Australian number one Bernard Tomic 7-6 (7/4), 6-4.
Tokyo: Second seed Jo-Wilfried Tsonga bludgeoned close friend Gael Monfils into submission with a 6-3, 7-6 victory in a first-round French rendezvous at the $1.43 million Japan Open on Monday.
World number seven Juan Martin del Potro heads the Tokyo field in the absence of Wimbledon champ Andy Murray, who pulled out to undergo minor back surgery.