OSAKA, Japan: Top-seeded Samantha Stosur of Australia advanced to the second round of the Japan Open by beating Erika Sema of Japan 6-4, 6-2 yesterday.

Stosur, who won the tournament in Osaka in 2009, had five aces and converted five of six break points at Utsubo Tennis Center.

The ninth-ranked Stosur reached the semifinals of the Pan Pacific Open in Tokyo earlier this month and is seeking her first title of the year.

Also, Chang Kai-chen of Taiwan defeated third-seeded Christina McHale of the United States 6-3, 7-6 (5), and Jamie Hampton of the United States beat Ayumi Morita of Japan 6-3, 6-2.

Pauline Parmentier of France, Casey Dellacqua of Australia, Heather Watson of Britain and Misaki Doi of Japan also advanced to the second round.

I’m not finished yet, warns

victorious Azarenka

Meantime, world No. 1 Victoria Azarenka warned she was planning to finish her breakthrough season with a flourish after ending a seven-month win drought at the China Open.

The 23-year-old from Belarus started the year with a bang by winning her first Grand Slam title at the Australian Open, along with trophies in Sydney, Doha and Indian Wells.

But Azarenka has repeatedly faltered at the last hurdle since, losing three finals including at last month’s US Open, where Serena Williams’ late recovery left her in tears.

On Sunday, she put her frustrations behind her with a 6-3, 6-1 thumping of world No. 2 Maria Sharapova to seal her fifth title this year, second only to Williams’ six. And afterwards, she said she was not finished yet.

“I have two more tournaments to play. It’s going to be about 10 more matches, so I’m looking forward to maximizing that potential in all of them,” Azarenka said. “It’s just going to be the last two pushes.

“I’m actually really happy that in the end of the year I am still able to have that determination I had in the beginning of the year and the desire to go out there and win and show my best tennis, to progress throughout difficult times physically and mentally.”

Azarenka will next play an indoor event in Linz as she prepares for the WTA Championships season finale, involving only the world’s top eight players, in Istanbul later this month.

Her 26-match winning streak at the year’s start was the best beginning to a season by any woman in 15 years. And the China win makes her the first player to win two premier mandatory events in a year, after her victory at Indian Wells.

“It’s an incredible feeling,” she said of the achievement. “I didn’t know the statistic before yesterday (Saturday). It’s definitely a great achievement, showing that I have been pretty consistent throughout the whole year.”

Azarenka finished 2011 in third place on the rankings but her breakthrough Australian Open win in January took her to the top spot, where she has spent much of the season.