Standing between the top seed and her first clay final since Prague in 2007 is Spanish seventh seed Anabel Medina Garrigues, a three-time champion, who put out Croatia's Mirjana Lucic 6-4, 6-4.
Qualifier Lucic, 29, was playing her first WTA quarter-final since she went all the way to the semi-finals at Wimbledon in 1999.
Friday's other semi-final pits German second seed Andrea Petkovic against Daniela Hantuchova, the Slovak sixth seed.
Petkovic defeated Russian fifth seed Maria Kirilenko 6-4, 6-3 while Hantuchova knocked out fourth seeded Russian Nadia Petrova 6-4, 6-2.
- AFPTags: sport, tennis, france