London – World No 1 Victoria Azarenka advanced to the Olympic quarter-finals with a 7-6 (8/6), 6-4 victory over Russian 16th seed Nadia Petrova on Wednesday.

Belarus's Azarenka took one hour and 54 minutes to see off Petrova in a hard-fought clash on Court One at the All England Club.

The reigning Australian Open champion will face five-time Wimbledon winner Venus Williams or German seventh seed Angelique Kerber for a place in the semi-finals. – Sapa-AFP