By Peter Simpson
BEIJING (Reuters) - Former world number one Maria Sharapova struggled into the second round of the China Open on Sunday with a labored 6-4 7-6 victory over unseeded Bulgarian Tsvetana Pironkova.
The Russian struggled to find consistency but did, however, avoid the fate of fourth seed Samantha Stosur who lost to Latvian qualifier Anastasija Sevastova 2-6 7-6 7-5.
China's leading player Li Na, seeded ninth, produced a crowd-pleasing 6-2 6-0 over Russian Alla Kudryavtseva at the Olympic tennis center in the Chinese capital.
A glum-looking Sharapova did not celebrate her progress against world number 32 Pironkova after a second set tiebreak ended the two hour, seven minute slog.
"The first rounds are always difficult. You just try to find your way and your rhythm," said 12th seed Sharapova.
"At the end of the day, I found a way to win and that was the most important thing today."
Sharapova, dumped out of the Tokyo Open in the first round by 40-year-old Japanese Kimiko Date Krumm last month, said she was struggling to find her form.
"I faced a tough opponent today," she said after an error-strewn match featuring fierce rallies and multiple break opportunities under a hot Chinese autumn sun and strong winds.
"I think consistency is one of my problems and I need to cut down on the errors. I had to change my motion after surgery on my shoulder." she added.
Unseeded Argentine Gisela Dulko caused an upset by knocking out Aravane Rezai 6-4 2-6 6-4.
Wozniacki, 20, is two victories away from taking the number one ranking following her Saturday tournament win in Tokyo and Beijing no-shows by the top players.
World number three Venus Williams pulled out due to injury just before the competition began, following her sister and world number one Serena who withdrew earlier.
U.S. Open champion Kim Clijsters pulled out of the event earlier in the week with a foot injury.
(Editing by Alison Wildey)