Former world number Caroline Wozniacki extended her recent revival Tuesday as she saw off Daniela Hantuchova in round two of the star-studded Pan Pacific Open in Tokyo.
Wozniacki, who won her first WTA title in more than a year in Seoul last week, beat Slovakia's Hantuchova 7-6 (7/3), 6-1 to stretch her Asian winning streak to seven matches.
The 22-year-old Dane, girlfriend of star golfer Rory McIlroy, has tumbled out of the top 10 and currently sits at 11. But her resurgence will face a test at the Pan Pacific Open, which features the cream of women's tennis.
In earlier results, French Open champion Maria Sharapova struggled past British qualifier Heather Watson, while Czech fourth seed Petra Kvitova, last year's Wimbledon winner, crashed to little-known Croatian Petra Martic.
Sharapova lost the first set and needed more than three hours before finally seeing off Watson, the world number 78, 6-7 (7/9), 6-3, 6-4.
"I was not consistent enough. I had opportunities to win the first set and I didn't," said Sharapova, the world number two. "It wasn't the best quality match."
The Russian hit nine aces but also had 14 double-faults.
"That certainly gave her a lot of confidence. I think that's the reason why the match was so long. My percentage (of first serves) was very low as well," said the second seed.
"So I put pressure on myself, I hit so many second serves. Certainly I have to improve for tomorrow."
Sharapova, 25, struggled with her serve throughout, hitting three double-faults in the 10th game of the first set.
She again hit three double-faults, one while on set point, at 6-5, and passed up two more set points before being edged out in the tie-breaker.
But Sharapova finally rallied, attacking Watson's second serve to hit a total of nine return winners and finish off the match.
World number one Victoria Azarenka of Belarus maintained her good form to beat Tamira Paszek of Austria 6-1, 6-1, while defending champion Agnieszka Radwanska of Poland eliminated Jelena Jankovic of Serbia 6-2, 7-5.
A badly off-form Kvitova double-faulted three times to lose the opening game against 73rd-ranked Martic, and then the set, and was always up against it after losing the first game of the second set to love. She was beaten 6-4, 6-4.
"She has a big serve and it is tough to push her. She kept me on the defensive and running a lot, and that's not my game. She played so well today, very aggressive," said Kvitova, 22.
Last year's French Open champion Li Na of China, seeded seventh, beat Anastasia Pavlyuchenkova of Russia 7-5, 4-6, 6-2, while ninth seed Marion Bartoli of France defeated Germany's Julia Goerges 6-2, 7-5.