Caroline Wozniacki continues winning streak by beating Nadia Petrova in Qatar . Schiavone , the reigning French Open champion , complained of tiredness after her defeat . Dane comes to Doha off the back of her Dubai Open success . Third seed and French Open champion Marion Bartoli is also at Doha having won last week's title in Paris. Second seed Vera Zvonareva reaches quarterfinals by beating Dominika Cibulkova .
Caroline Wozniacki continues winning streak by beating Nadia Petrova in Qatar . Dane comes to Doha off the back of her Dubai Open success . Third seed and French Open champion Marion Bartoli is also at Doha having won last week's title in Paris. Second seed Vera Zvonareva reaches quarterfinals by beating Dominika Cibulkova .