Azarenka advances in Brisbane

Brisbane - Former world number one Victoria Azarenka moved into the quarter-finals of the Brisbane International when she downed little-known Belgian Ysaline Bonaventure 6-3, 6-2 on Wednesday.

Bonaventure, who had lost in the final qualifying round, gained a main draw spot when top seed Simona Halep pulled out with a leg injury on Tuesday.

She pushed the two-time grand slam winner hard, particularly in the 56-minute first set when she blasted 18 clean winners.

But once Azarenka weathered the storm she was able to master the 21-year-old Belgian and was never really troubled thereafter.

"I think the beginning definitely was really tough," said 26-year-old Azarenka.

"She played very well. You know, it's always a little bit of a moment of adaptation when you don't know who you play, so it's an adjustment.

"But I'm glad I could stay strong in the beginning and turn it around, because it wasn't going my way at first for sure."

Azarenka spent 51 weeks as world number one in 2012 but suffered a severe foot injury in 2014, finishing the year at 32.

She was then hampered by a left thigh problem in 2015, which affected her climb back to the top 10.

Azarenka started the year at number 22 and is unseeded this week.

She said she was pleased with how she had been able to take control of the match midway through the first set.

"I think just to feel the momentum shift in the match was important, you know, in the beginning of the year," she said.

"Especially since I haven't played in a while. So it's good to go through those moments."

Azarenka will play 2015 US Open runner-up Roberta Vinci in the quarter-finals.

"She's been playing really well and showing some great results," Azarenka said of the eighth-seeded Italian.

"I think you can see improvement in her game. I think she's just on the rise and she feels really good, confident."

Fourth-seeded German Angelique Kerber was impressive in her 6-3, 6-0 demolition of American Madison Brengle.

The world number 10 will now take on Russia's Anastasia Pavlyuchenkova in the quarter-finals.

Little-known American Samantha Crawford upset seventh-seeded Swiss Belinda Bencic 7-5, 7-5 in 90 minutes.

The qualifier from Florida will now take on Germany's Andrea Petkovic, who ousted Russia's Ekaterina Makarova 7-5, 6-4.

Petkovic conceded she knew nothing of the 20-year-old Crawford.

"I don't know anything - it's going to be classic YouTube stalking from my side," she said.

"I don't know if I'm going to find a lot, but she must be playing tremendously well to beat Bencic and win three qualifying rounds."