Samantha Stosur is out of the Indian Wells Masters, beaten by Italian veteran Flavia Pennetta in the third round.

Pennetta accounted for world No.17 Stosur 6-4 3-6 6-1 on Monday.

The 32-year-old set up a clash with Italian qualifier Camila Giorgi who stunned defending champion and fourth seed Maria Sharapova 6-3 4-6 7-5.

In a match in which both players struggled to hold serve, the 79th-ranked Giorgi needed two hours and 36 minutes to notch her first career win against a top-10 player.

Earlier, Australian Open champion Li Na booked her fourth-round berth with a 6-3 6-4 victory over Karolina Pliskova of the Czech Republic.

Li, the world No.2 and top seed, is seeking her third title of 2014.

She lifted the trophy in Shenzhen in her native China before claiming the second Grand Slam crown of her career in Melbourne in January.

In men’s action fifth seed Andy Murray had a tough 6-7 (7-2) 6-4 6-4 win over Jiri Vesely, Stanislas Wawrinka dispatched Andreas Seppi 6-0 6-2 and Roger Federer edged Dmitry Tursunov 7-6 (9-7) 7-6 (7-2).