Updated

The world's top-two women's tennis stars, Victoria Azarenka and Maria Sharapova, were a pair of second-round winners Tuesday at the $5.190 million Madrid Open.

The world No. 1 Azarenka committed nine double faults but still got past Czech qualifier Andrea Hlavackova 6-3, 7-6 (7-2) in 1 hour, 45 minutes, while the former No. 1 Sharapova cruised past the Czech Republic's Klara Zakopalova 6-4, 6-3 on the unusual blue clay surface at The Magic Box. The Aussie Open and Wimbledon runner-up Sharapova has now won her last six matches overall, is 24-4 for the year, and will encounter Czech Lucie Safarova in the round of 16.

The Belarusian Azarenka, now 31-2 in 2012, beat Sharapova in January's Aussie Open final, but the Russian avenged the setback with a victory in final in Stuttgart just two weeks ago.

Azarenka was last year's Madrid runner-up to Wimbledon champion Petra Kvitova.

Up next for Azarenka will be 13th-seeded former world No. 1 Ana Ivanovic, who bested former top-10 player Nadia Petrova of Russia 7-5, 6-1. Azarenka and the Serbian Ivanovic will square off on Wednesday.

In some other second-round action, Spain's Anabel Medina Garrigues held off Romanian Sorana Cirstea 6-1, 3-6, 7-5, American qualifier Varvara Lepchenko beat struggling Israeli Shahar Peer 7-6 (7-2), 6-4, and the aforementioned Safarova topped Spanish wild card Carla Suarez Navarro 6-3, 6-4. Suarez was fresh off her clay-court runner-up finish in Estoril last week.

In addition to the Australian Open champion Azarenka, U.S. Open champion Sam Stosur and French Open titlist Li Na will also see third-round action on Wednesday.

And a third-seeded Kvitova and world No. 4 Agnieszka Radwanska will be among those seeing second-round action on Wednesday, as Kvitova will take on fellow Czech Lucie Hradecka and the Polish Radwanska will be opposed by hot Italian Sara Errani, who already owns three titles this year, including one in Budapest last week.

This year's Madrid Open winner will earn $830,500.