The ninth-seeded Kerber upended the Australian Open runner-up Sharapova 6-4, 6-4 at Stade Pierre de Coubertin. The 24-year-old German piled up five service breaks, while the former world No. 1 Sharapova settled for three.
Kerber was a surprise U.S. Open semifinalist in September.
Second-seeded French crowd favorite Marion Bartoli barely avoided an upset, as the former Wimbledon runner-up came from behind to outlast seventh-seeded Italian Roberta Vinci 4-6, 6-4, 7-6 (7-2) in 2 hours, 40 minutes.
The hard-hitting Bartoli is trying to become the first Frenchwoman to title here since former world No. 1 Amelie Mauresmo turned the trick in 2009.
Bartoli's semifinal opponent on Saturday will be Czech veteran Klara Zakopalova, who upset sixth-seeded German Julia Goerges 3-6, 7-5, 6-1. Kerber will face Belgian Yanina Wickmayer, who defeated Kerber's German compatriot Mona Barthel 6-4, 6-7(3-7), 6-3 in Friday's final match.
The winner of this $637,000 event will pocket $107,000.