NEW YORK, NY, USA - World No.1 Victoria Azarenka became the second player to reach 50 wins on the season on Wednesday, cruising past Kirsten Flipkens in a routine straight-setter in the second round of the US Open.

After an abbreviated summer hardcourt lead-up season that saw her play just one match - retiring after just six games in Montréal due to a knee injury - Azarenka has blown through her first two opponents in New York, crushing Alexandra Panova in the first round, 60 61, and now beating Belgian qualifier Flipkens on Arthur Ashe Stadium on a very windy Wednesday, 62 62.

"I think it was a good performance. It was difficult with the wind, but I adjusted really well," Azarenka said. "Her game was also a little bit unpredictable. She likes to move her opponent around and has a lot of variety, and maybe it wasn't as easy as the score looks, but I moved well, which is important in the wind."

Flipkens hit a lot of slice during the match - Azarenka talked about adjusting to that kind of spin. "I practiced yesterday for that," she said. "She has a really deep slice and it's a little bit tricky. It took me a few shots to get a feel for her ball, but I had to stay aggressive and not let her command with that shot."

Azarenka is now second on the WTA match win leaders list for the season with 50, trailing only Angelique Kerber, who has 54. Agnieszka Radwanska could become the third player to get to 50 if she wins her match on Thursday.

Next up for Azarenka is No.28 seed Zheng Jie, who blasted 20 winners and never lost serve to beat Slovakian qualifier Magdalena Rybarikova, 63 61.

"She's definitely a really tough opponent - she's had big matches and big results," Azarenka said of the Chinese. "It's going to be interesting. We haven't played in a while. I actually don't remember the last time we played."

Azarenka leads Zheng in their head-to-head series, 2-1, and their last meeting came almost three years ago in Tokyo, with Azarenka cruising. But Zheng has had two career wins over reigning World No.1s, over Ana Ivanovic at Wimbledon in 2008 and against Dinara Safina at Los Angeles in 2009.

"I kind of need to step it up in the later rounds coming up," Azarenka said. "She can definitely show good tennis. I look forward to playing that match."

Whoever wins between Azarenka and Zheng will have somewhat of a surprise package in the fourth round, either Mandy Minella or Anna Tatishvili. Minella was the first of the pair to advance, beating Czech qualifier Kristyna Pliskova, 64 64; Tatishvili followed with a 67(5) 61 62 victory over Sorana Cirstea.

Tatishvili beat Minella in the pair's only previous meeting. Neither player has ever been to the second week of a Grand Slam in their career - in fact they only have one career Grand Slam third round appearance between them, that being Minella here at the US Open in 2010 (falling to Venus Williams).