The reigning Roland Garros holder will play Ana Ivanovic after the Serb ninth seed defeated Ukrainian teenager Elina Svitolina 6-2, 6-3 in less than an hour on Friday night.
Sharapova, a five-time Grand Slam champion, has won eight of 11 meetings with her former world number one opponent. Ivanovic claimed their last meeting in the third round at Rome in May.
Sharapova had to make a great escape against world number two Halep, who has burst into WTA prominence over the past year. Sharapova won her fifth match against Halep without a loss.