Second seed Maria Sharapova has been knocked out of the BNP Paribas Open following a 3-6 6-3 6-2 defeat to Flavia Pennetta in the fourth round at Indian Wells.

Both players lost their serve in a nervy opening to the contest, but there were signs that Sharapova was beginning to find her form as she broke again to take the first set.

However, it soon became clear that the two-time winner was not at her best, and Pennetta started to punish errors with an attacking approach.

The 15th seed was rewarded for her improvement with a break of serve in the sixth game, and she survived a scare on her own serve to level the score.

Sharapova struggled to produce a response, and Pennetta took full advantage by dictating the tempo throughout the decider to earn two breaks.

The Italian refused to show any signs of nerves after racing into a 5-1 lead, and she secured an impressive victory with a comfortable win in the third set.