The Russian, seeded No. 3, beat Kim Clijsters of Belgium 6-2, 7-5 on Centre Court at Wimbledon to reach the Olympic semi-finals.
Sharapova's opponent on Friday will be No. 14 Maria Kirilenko of Russia, who defeated No. 6 Petra Kvitova of Germany 7-6 (3), 6-3.
Sharapova hit 25 winners to eight for Clijsters, who plans to retire after the U.S. Open.