Azarenka's reward is a clash with unseeded German Anna-Lena Groenefeld, who beat Australia's Alicia Molik 6-4 6-4.

CNN: STORY HIGHLIGHTS

Fourth seed Angelique Kerber came through in three sets against Georgia's Anna Tatishvili, while her fellow German Sabine Lisicki beat Czech Lucie Safarova 6-2 6-4.

CNN: STORY HIGHLIGHTS

In the only other first-round match on the opening day, Spain's Conchita Martinez ousted the only German player in the main draw, wild card Anna-Lena Groenefeld, 7-6 6-2.

BBC: SPORT | Tennis | Clijsters: Serena still the best