Azarenka, the world No. 1, dispatched Romina Oprandi 6-2, 6-0 in a brisk 55 minutes. Azarenka won 74 percent of the points off Oprandi's serve, winning all six of her break-point opportunities.
Sharapova, second in the world rankings, won the first nine games of her match before fifth-seeded Angelique Kerber retired with a right foot injury. Sharapova won two-thirds of the points on serve -- saving five break points -- and 60 percent when receiving serve.
China's Li Na ousted defending champion and third-ranked Agnieszka Radwanska 6-4, 6-2 without dropping serve. She lost just 14 points on serve while breaking Azarenka's serve three times.
Ninth-seeded Marion Bartoli survived a seesaw third set in a 6-0, 2-6, 6-4 win over Carla Suarez Navarro. They traded a series of breaks before Bartoli's third of the third set put her up 5-4 and she held serve for the win.
Azarenka is matched against Bartoli and Sharapova goes against Li in the semifinals Saturday. Azarenka holds an 8-3 series edge over Bartoli after they split two matches in 2012. Sharapova won both meetings with Li this year and improved to 7-4 in her career versus Li.