Sharapova won nearly two-thirds of the points overall in a 6-0, 6-2 decision over Polona Hercog. Sharapova landed a very strong 82 percent of her first serves and saw only one break point. She had six breaks in Hercog's seven games serving.
No. 1-seed Victoria Azarenka was also a straight-set winner, beating Elena Vesnina 6-3, 6-3. Despite nine double faults, Azarenka dropped serve just once and had a pair of breaks in each set.
Fifth-seeded Angelique Kerber posted a 6-1, 2-6, 6-4 win over 10th-seeded Caroline Wozniacki. Kerber ended up with five breaks, including the only one recorded in the third set.
Li Na, the seventh seed, was a 4-6, 6-4, 7-6 (7-2) winner over Peng Shuai in a battle between two of China's best women's tennis players.
Azarenka goes against Romina Oprandi while No. 9-seeded Marion Bartoli takes on Carla Suarez Navarro in the quarterfinals in one half of the draw. The other matches have Li meeting defending champion and third-seeded Agnieszka Radwanska and Sharapova playing Kerber.