Top-ranked Victoria Azarenka withdrew from the Rogers Cup on Friday because of a knee injury.

Azarenka, who had a first-round bye, was tied 3-3 in her second-round match against Tamira Paszek when it was suspended by rain Thursday night.

The 23-year-old Belarusian won two Olympic medals in London, taking gold in mixed doubles and bronze in singles.

Meanwhile Petra Kvitova of the Czech Republic dispatched Marion Bartoli 6-1, 6-1 at Uniprix Stadium.

Kvitova advanced to the quarterfinals where she will face the winner of the third-round match between Paszek and Carla Suarez Navarro.

Azarenka joins second-ranked Maria Sharapova, who withdrew Wednesday because of a virus.