Two more seeds went down at the Internationaux de Strasbourg, but No.3 seed Alizé Cornet and No.7 seed Chanelle Scheepers set up a quarterfinal showdown.
Serena Williams' two titles and perfect 15-0 record have cast a shadow over the 2013 clay court season and on Sunday she looks to round off her French Open preparations with victory at the Foro Italico.
Sara Errani and Roberta Vinci stayed on course to defend their Rome doubles title with a 62 61 semifinal win over Alla Kudryavtseva and Anastasia Rodionova on Saturday evening.
Nadia Petrova and Katarina Srebotnik's return to form continued with a routine win over Jelena Jankovic and Mirjana Lucic-Baroni at the Internazionali BNL d'Italia on Friday.
Simona Halep takes on Serena Williams and her 22-match winning streak, looking to become the first Romanian to reach the Rome final since Virginia Ruzici in 1981.