Nadia Petrova reaches fourth round , beating Maria Jose Martinez Sanchez . World No . 1 will play Alisa Kleybanova for a place in Russian Petrova quarterfinals . Peng Shuai will be Petrova 's next challenger , with the Chinese player earning a hard-fought 6-3 4-6 7-5 win over Czech qualifier Lucie Hradecka . Maria Sharapova sets up last-16 clash with fellow Indian and former No . 1 Dinara Safina . Maria Sharapova , Agnieszka Radwanska and Victoria Azarenka also progress .
Nadia Petrova reaches fourth round , beating Maria Jose Martinez Sanchez . World No . 1 will play Alisa Kleybanova for a place in Russian Petrova quarterfinals . Maria Sharapova sets up last-16 clash with fellow Indian and former No . 1 Dinara Safina . Maria Sharapova , Agnieszka Radwanska and Victoria Azarenka also progress .