Samantha Stosur has been beaten by 82-ranked Jana Cepelova in the second round in difficult conditions at the WTA Qatar Open.
Paying on outside court where the blustery wind was a big factor, world No.16 Stosur went down 6-4 4-6 6-1 to the 20-year-old Slovakian in Doha.
The 12th seeded Australian was in good company, with among half of the 16 seeds gone by midway through the third day.
Australian Open champion Li Na bucked the trend but had to battle hard in her return to action after last month's grand slam triumph.
The top-seeded Chinese player needed two and a quarter hours to overcome blustery wind and Slovakian Magdalena Rybarikova, the world No.32, 6-1 5-7 6-2, reversing the result of their only previous meeting in 2009.
Ana Ivanovic, the ninth-seeded former French Open champion, lost 4-6 6-1 6-3 to world No.34 Klara Zakopalova.
On centre court Petra Kvitova, the third-seeded former Wimbledon champion, pulled off a 6-2 2-6 7-6 (9-7) win over Venus Williams, the seven-times former Grand Slam champion who produced flashes of her formidable best.
Williams led 4-1 in the final set and would have reached 5-1, with a double break of serve, had she not unaccountably put a drop shot into the net with the court wide open.
Later another seed departed when Caroline Wozniacki, the eighth-seed, lost cold late night encounter with Yanina Wickmayer 6-4 7-5.
