Errani won just two more points --136-134 -- over the course of the match but she had one more break and that was the difference in the decisive third set.
Kristina Mladenovic finished off a long day of quarterfinals with a 6-3, 6-4 upset of Kvitova. She had three breaks in the first set and two more in the second, giving her breaks in half of Kvitova's serving games.
Mona Barthel came away a 7-6 (9-7), 6-4 winner over Bartoli. Barthel won nearly three-quarters of the points on serve and used a pair of breaks to eliminate Bartoli.
Kiki Bertens ousted Safarova 6-1, 7-5, winning 53 percent of the points off Safarova's serve. She lost just 11 points in the first set.
Errani draws Bertens, whom she beat in their only previous meeting, in Saturday's semifinals. Barthel is 2-1 versus Mladenovic, with all those matches in 2011.