Azarenka, even though she lost serve once, routed Tamira Paszek 6-1, 6-1 in 63 minutes. Azarenka lost 10 points -- four in the game she was broken -- over seven service games. She also won 63 percent of the points off Paszek's serve.
Second-seeded Maria Sharapova need to rally for a 6-7 (7-9), 6-3, 6-4 decision over Heather Watson in a match that took more than 3 hours. Sharapova had nine aces but also 14 double faults. However, she won one more (54-53) point off Watson's serve than Watson managed.
Agnieszka Radwanska, the tournament defending champion and No. 3 seed, got by Jelena Jankovic 6-2, 7-5 before six service breaks. Radwanska took 54 percent of the points off Jankovic's serve.
Petra Martic ousted fourth-seeded Petra Kvitova 6-4, 6-4 with a total of five breaks. In other upsets Tuesday, Urszula Radwanska defeated 11th-seeded Ana Ivanovic 3-6, 6-4, 6-2 and qualifier Jamie Hampton edged past No. 15 Kaia Kanepi 5-7, 6-2, 6-3.
Fifth-seeded Angelique Kerber stopped Ayumi Morita 6-3, 6-4 while No. 6 Sara Errani won a 6-4, 7-6 (7-1) match over Johanna Larsson. No. 7-seeded Li Na outlasted Anastasia Pavlyuchenkova 7-5, 4-6, 6-2 and eighth-seeded Samantha Stosur advanced on a 4-6, 6-2, 7-5 win over Francesca Schiavone.
Other second-round winners Tuesday were: ninth-seeded Marion Bartoli, No. 10-seeded Caroline Wozniacki, 12th-seeded Dominika Cibulkova, No. 14 Roberta Vinci; 16th-seeded Lucie Safarova and No. 17-seeded Nadia Petrova.