Seventh seed Anna Chakvetadze of Russia was upset in the first round of the Tennis.com Zurich Open by Romanian qualifier Monica Niculescu 3-6 6-3 6-2. Sixth seed Patty Schnyder of Switzerland lost to qualifier Petra Kvitova 6-4 3-6 6-4.
The world No.66 Niculescu won 10 of the final 13 games with her left thigh heavily strapped.
Chakvetadze was the second seeded player to lose at the Tennis.com Zurich Open as eighth seed Daniela Hantuchova of Slovakia fell to Maria Kirilenko of Russia on Monday.
Later on Tuesday, Schnyder was upset by the world No.57 Kvitova of the Czech Republic, in three sets like Chakvetadze.
Other today’s results: Italy’s Francesca Schiavone beat Caroline Wozniacki of Denmark 7-6(3) 6-2, and Marion Bartoli of France defeated Hungarian Agnes Szavay 6-4 6-0.