Venus Williams and Samantha Stosur were among the winners at the $5.189 million Madrid Open on Saturday.

A wild card here, Williams cruised through the first set, six games to one, but then committed six double-faults in the ensuring two sets as she limped to a 6-1, 4-6, 7-6 (8-6) victory over Simona Halep in almost 2 1/2 hours.

The reigning U.S. Open champion, Stosur, also went three sets and a tiebreak in her bout with Croat Petra Martic. The fifth seed held on for a 7-5, 4-6, 7-6 (7-5) decision on the all-new blue clay surface at The Magic Box.

Despite handling current world No. 1 Victoria Azarenka in the Sony Ericsson Open earlier this year, seventh-seeded Marion Bartoli could not handle unseeded Sorana Cirstea, falling 6-7 (6-8), 6-4, 6-3.

Li Na -- current French Open titleholder -- and American upstart Christina McHale were also winners on Day 1. The eighth-seeded Li bested Garbine Muguruza Blanco 6-2, 6-4, while McHale emerged victorious in 6-4, 7-5 fashion.

Other first-round winners Saturday included wild card Silvia Soler-Espinosa, 6-7 (2-7), 6-2, 6-2 over Tamira Paszek; Petra Cetkovska over 10th-seeded Vera Zvonareva, 6-2, 6-2; Mona Barthel over Julia Goerges, 6-4, 6-1; and Klara Zakopalova over Iveta Benesova, 6-4, 7-6 (7-5).

This week's top seeds are Azarenka, last week's Stuttgart champion Maria Sharapova and Petra Kvitova. The 2011 Wimbledon champ Kvitova bested the 2012 Australian Open titlist Azarenka in last year's marquee Madrid finale. The former No. 1 Sharapova upset Azarenka in the recent Porsche Tennis Grand Prix title tilt.

Other former No. 1s in the field here are 2009 Madrid runner-up Caroline Wozniacki, Serena Williams, Ana Ivanovic and Jelena Jankovic.

The 2012 Madrid Open champ will earn $830,500.