Third-seeded Dominika Cibulkova withstood a three-set test in advancing to the quarterfinals of the Qatar Open on Wednesday at Doha, Qatar.
Cibulkova, the world's fifth-ranked player from Slovakia, posted a 7-5, 2-6, 6-2 second-round victory over Anastasia Pavlyuchenkova of Russia.
"It's not easy to play Anastasia," Cibulkova said after the match. "We've played so many matches together and this match was one of the good ones."
Pavlyuchenkova, the only player to complete her match in Tuesday's rainy conditions, was broken early in the third and trailed 4-1 in the third set before another brief rain delay.
"I was hoping that the rain delay would help me to settle down and get my emotions cooled down," said Cibulkova, who earned another break en route to closing out the match.
Zhang Shuai of China also advanced to the quarterfinals by winning a pair of matches Wednesday, including an upset of No. 5 seed Garbine Muguruza, 7-6, 3-6, 7-5 in her second-round match.
Zhang started the day by dispatching Timea Babos to set up a match against French Open champion Muguruza, who was playing her second match of the day after ousting Turkey's Cagla Buyukakcay 6-3, 6-2.
"I woke up thinking that I was going to have a very tough day," Muguruza said. "I played pretty good the first match. The second one, Zhang played very well."
Monica Puig of Puerto Rico reached the quarterfinals, leading 6-4, 4-6, 2-1 when Yulia Putintseva was forced to retire in the third set. Up next for Puig is the winner of the match between top seed Angelique Kerber and Daria Kasatkina.
No. 6 seed Elena Vesnina and eighth-seeded Barbora Strycova won their first-round matches while seventh seed Timea Bacsinszky retired after dropped the opening set to Putintseva.
Former world No. 1 Caroline Wozniacki also won her first-round match, rallying from a pair of 0-2 deficits in a straight-set win over Kiki Bertens.