Madrid - A pair of women's seeds were bundled out of the Madrid Masters on Tuesday, as Aussie Samantha Stosur continued her fine run on clay by dispatching last week's Rome champion, Maria Jose Martinez Sanchez.
Stosur prevailed 7-6 (7/2) 6-4 and will next play Swiss veteran Patty Schnyder, who upset Polish number nine seed Agnieszka Radwanska 3-6 6-4 6-4.
Schnyder, aged 31 and ranked 48th in the world, mounted a comeback to stun Radwanska for a 2-1 lead in their head-to-head series.
The Swiss broke six times in the two-hour victory, her tenth of a modest season against eight losses.
Stosur, a French Open semi-finalist last year, has bloomed on the clay this spring, winning Charleston and reaching the final in Stuttgart. She has won 13 of her last 14 matches on the surface.
The Australian posted her 25th victory of the season with the elimination of Martinez Sanchez, who beat Serbia's Jelena Jankovic for the Italian title at the weekend.
Martinez Sanchez saved a match point to hold serve in the penultimate game before Stosur earned victory.
Stosur has now beaten Martinez Sanchez three times in 2010, the previous two times on hardcourt at the Fed Cup and at the Indian Wells quarter-finals.
German Andrea Petkovic upset Italian 14th seed Flavia Pennetta 7-6 (7/3) 6-3 while Czech Lucie Safarova followed up her first-round win over three-time Grand Slam champion Maria Sharapova with a 4-6 6-2 7-5 second-round win over Olga Govortsova of Belarus.
Russian world number 18 Nadia Petrova defeated compatriot Anastasia Pavlyuchenkova 6-2 7-5.