Victoria Azarenka and Roger Federer advance in Australia

Defending champion Victoria Azarenka strolled into the quarter-finals with a simple win against Elena Vesnina, remaining on course for a semi-final with Serena Williams.
World number one Azarenka triumphed 6-1 6-1 to book a meeting with Svetlana Kuznetsova, who knocked out 10th seed Caroline Wozniacki.
Williams, who has lost just once since her first round exit at last year's French Open, produced a dominating performance in her 6-2 6-0 victory over Maria Kirilenko.
In the men's draw, four-time Australian Open champion Roger Federer was also in convincing form with a straight sets win over Milos Raonic, setting up a quarter-final with Jo-Wilfried Tsonga.