Istanbul, Turkey:Venus Williams' preparations for the French Open were disrupted on Wednesday when she lost in straight sets to Aravane Rezai at the Istanbul Cup.
The 62nd-ranked French player beat the fourth-seeded Williams 6-4, 6-4 in the second round of the clay-court tournament.
Rezai will face Meghann Shaughnessy of the United States in the quarterfinals.
Also Wednesday, the second-seeded Elena Dementieva of Russia beat Croatia's Jelena Kostanic Tosic 6-3, 6-2 and will next meet Catalina Castano of Colombia.
Patty Schnyder of Switzerland beat Vania King of the United States 6-4, 6-1 to set up a quarterfinal meeting with Ukraine's Alona Bondarenko.
The French Open starts on Sunday.