World No. 1 Victoria Azarenka and Spanish fourth seed David Ferrer advanced at the US Open with straight-set victories on Wednesday at the season's final Grand Slam event.

Azarenka reached the third round by defeating Belgian qualifier Kirsten Flipkens 6-2, 6-2 in only 65 minutes at Arthur Ashe Stadium.

Reigning Australian Open champion Azarenka, who has reached the last eight in every Grand Slam event except the US Open, will next face Chinese 28th seed Zheng Jie, who beat Slovakian qualifier Magdalena Rybarikova 6-3, 6-1.

The 23-year-old from Belarus, whose 26-match win streak to begin the season was the best women's start since 1997, seeks her 13th career title and fifth trophy of the year on the Flushing Meadows hardcourts.

"I would love to play for the title," Azarenka said. "It's a long way. It's just the second round now."

Ferrer, who became best man in a quarter of the draw when compatriot Rafael Nadal pulled out with knee problems, defeated South Africa's Kevin Anderson 6-4, 6-2, 7-6 (7/3).

"I'm happy. I played good. I tried to play solid and consistent and very good with my first serve," said Ferrer, who connected on 64 percent of his first serves.

Ferrer, whose best Grand Slam showing was a 2007 US Open semi-final run, booked a second-round match against Dutch qualifier Igor Sijsling, who beat Spain's Daniel Gimeno-Traver 7-5, 6-3, 6-4.

Only World No. 1 Roger Federer has won more titles this year than Ferrer, whose crowns include Auckland, Acapulco, Buenos Aires, s-Hertogenbosch and Bastad.

America's Brian Baker, who lost six years of his career to an assortment of injuries, reached the second round with a 6-3, 6-4, 6-2 victory over Czech Jan Hajek.

Baker, who reached the second round of the French Open and fourth round at Wimbledon in his first Slams since the 2005 US Open, will next face Serbian eighth seed Janko Tipsarevic, who rallied past French wildcard Guillaume Rufin 4-6, 3-6, 6-2, 6-3, 6-2.

Trying to break a trend that has seen women's top seeds fail to take titles at the past seven Grand Slams, Azarenka could be dethroned from the top ranking by Agnieszka Radwanska or Maria Sharapova if she fails to make the final.

Azarenka, who took a singles bronze medal at the London Olympics, broke 133rd-ranked Flipkens in the third and seventh games and took the first set in 27 minutes.

Azarenka broke again in the fifth and seventh game of the second set and held serve to close out the match, pumping her right fist in celebration after a winner on match point after her 50th victory of the season.

"I'm proud of everything I have achieved this season," she said. "It has been a great year."

Azarenka handled a morning curtain call as well as she had a late-night match on day one.

"It just depends on how I sleep," she said. "The first match was late at night. I adjusted pretty good. It doesn't matter what time I play. It matters how well I play on the court."

US 21-year-old US wildcard Mallory Burdette, ranked 252nd, booked her place in the third round with a 6-2, 6-4 victory over Czech Lucie Hradecka. She could face idol Sharapova next.

"I've always looked up to Maria," Burdette said. "I would love to certainly play more like her."

Hard-serving John Isner, the fortnight's top hope to end a nine-year US men's Grand Slam title drought as the ninth seed, begins his quest against Belgian Xavier Malisse.

Three-time US Open champion Kim Clijsters, playing her farewell event, risks her 22-match New York win streak against Britain's Laura Robson in a second-round match.

And third seeds Sharapova and Andy Murray of Britain take the court in night matches at Arthur Ashe Stadium, Olympic champion Murray trying to become the first man into the third round.