Second seed dispatches Kaia Kanepi to set up clash with Kvitova.
Straight-forward progress to semi-finals for Sharapova
Maria Sharapova is one win away from a first French Open final after seeing off Kaia Kanepi 6-2 6-3 in the quarter-finals at Roland Garros.
The second seed and title favourite is looking to complete her set of grand slam titles and go one better than last year, when she lost to eventual champion Li Na in the last four.
Sharapova had struggled in the wind against Klara Zakopalova in the previous round, dropping her first set of the tournament, and it was breezy and cool again today.
There had been a remarkable 21 breaks of serve in that match, and it looked like the same could happen today when all of the first three games went against serve.
But Sharapova looked much more secure, powering groundstrokes, and after she held for 3-1 she wasted little time racing through the rest of the first set.
Kanepi, who ousted former world No 1 Caroline Wozniacki in the third round, packs plenty of punch herself and she began the second set brilliantly, winning the first two games.
The Estonian had a chance to go 3-0 up but she could not take it, and from there Sharapova turned the screw, winning five successive games.
Kanepi had one last big effort, breaking the Russian to love when she served for the match, but she could not hold her own serve and a mis-hit backhand sealed her fate.
Sharapova will face fourth-seed Petra Kvitova of the Czech Republic rwho defeated qualifier Yaroslava Shvedova of Kazakhstan 3-6, 6-2, 6-4.
Shvedova, 24, had knocked out defending champion Li Na of China in the fourth round and would have been the first qualifier to make it to the women's semi-finals at Roland Garros.
Kvitova, 22, was broken in the second game and failed to convert three break points in the next, giving the Kazakh a quick 3-0 advantage.
The Czech held to 3-1 and took more chances in the fifth game to break Shvedova to 2-3 and put the match back on serve.
But Kvitova was broken again when a backhand return clipped the net and went wide, and in the next game hit a forehand long to give the Kazakh a 5-2 lead.
Shvedova came out firing in the opening game of the second set, breaking Kvitova with a cross-court backhand return.
Kvitova evened the score to 1-1 and held serve to nose ahead for the first time in the match before breaking Shvedova to consolidate her lead at 3-1.
Kvitova sprinted to 5-2 and then broke Shedova one more time to set up the deciding set.
The Wimbledon champion opened that with an easy hold and proceeded to break Shvedova to 2-0, but threw away the third game with two double faults and two unforced errors, enabling Shvedova to equalise at 2-2.
In the fifth game, as it began to drizzle on Suzanne Lenglen court, Kvitova missed an easy forehand return to give Shvedova two break points, and then hit a forehand long to give the qualifier a 3-2 lead.
Shvedova saved two break points to hold to 4-2.
Undaunted, Kvitova held in the seventh game and immediately put pressure on Shvedova's serve to level the match at 4-4, followed by a crucial hold.
Serving at 4-5, nerves got the better of Shvedova, allowing the world No 4 to convert her second match point for a place in the semi-final with Sharapova.