INDIAN WELLS, CA, USA – Victoria Azarenka clinches a berth in the second week of the BNP Paribas Open for the fifth time in her career, holding off a surging Zhang Shuai, 6-4, 6-3.

The Chinese wildcard is in the midst of a career-best season, having reached the quarterfinals of the Australian Open as a qualifier, and upset former No.1 Caroline Wozniacki less than 48 hours ago to set up the meeting with Azarenka, the 2012 champion in Indian Wells.

“She’s a very tricky opponent,” Azarenka admitted to Andrew Krasny after the match. “She’s playing with so much confidence and so free, and it’s the first time we’ve played each other. So, at the beginning it’s always a moment of adaptation, and she returned really well.

“I felt like I didn’t do enough on my service games and I had to step it up because she kept playing really aggressive and taking control. So, I’m glad I was able to put it in my hands.”

Adapt Azarenka did as the math unfolded, striking 27 winners to 13 from Zhang, and keeping her error count low, as well – 23 to 30. Edging ahead by an early break in the second set, Azarenka showed off some impressive gets in the last game to break Zhang once more to earn the final spot in the round of 16.

“Last year, I was a little slow. This year is definitely a different year. I’m glad I keep improving my speed; it’s so important in today’s tennis to be prepared physically so I’m really working on that.

“I’m glad that all the work off court is paying off on court.”

Up next for the former No.1 is No.26 seed and 2011 US Open champion Samantha Stosur, who outlasted a fiesty Christina McHale, 6-4, 2-6, 6-4.

As night fell on Indian Wells, 18-year-old Daria Kasatkina emerged victorious after a titanic effort against Puerto Rico’s Monica Puig; the young Russian led 3-0 in the final set but had to turn things around in a hurry when she found herself down match point at 4-5.

Making her BNP Paribas Open debut, Kasatkina broke Puig in that all-important tenth game and despite missing out on two match points of her own at 6-5, she displayed impressive tenacity in the final set tie-break, setting up a fourth round encounter with Timea Bacsinszky with a 6-4, 3-6, 7-6(2) victory.

“I’m a little bit tired, but I’m happy because, even though I didn’t play my best tennis over three sets, in the last three games I started to play better, so it means that I’m improving,” she said after the match.

“From the first practice, I feel like my spins are flying and the balls are good, so I like to play here because it’s a good surface for me.”