Doha, Qatar, 13 February 2014 | tennis.com.au

Sam Stosur has been upset in the second round of the WTA Qatar Total Open by 20-year-old Jana Cepelova.

The Slovakian scored her first ever top 20 win with the 6-4 4-6 6-1 defeat of 16th-ranked Stosur, seeded No.12 at the $2.44 million Premier-level event in the Middle East.

Stosur reached the final in Doha in 2012 but was unable to replicate that feat two years on, struggling on serve; she won just 32 per cent of points on her usually solid second delivery.

The 82nd-ranked Cepelova next faces Yanina Wickmayer of Belgium – who ousted No.8 seed Caroline Wozniacki – in the round of 16.

The seeded carnage continued in Doha when ninth seed Ana Ivanovic fell to Czech Klara Zakopalova.