Intro:

Maria Sharapova suffers a shock defeat by Flavia Pennetta at the BNP Paribas Open. Briton Heather Watson is also eliminated but there are wins for Simona Halep and Serena Williams in California.

Script:

Second seed Maria Sharapova suffered a surprise Indian Wells fourth round exit at the hands of world number 16 Flavia Pennetta 6-3, 3-6, 2-6.

Pennetta says she'll go into her quarter-final with 24th seed Sabine Lisicki in high spirits:

SOUNDBITE: (English) Flavia Pennetta

"I am really happy about this match tonight. From the beginning I knew it would be a really tough match but I tried to play my tennis, tried to be aggressive and everything was working pretty good tonight so I am really happy about this win."

Briton Heather Watson was eliminated by Spain's Carla Suarez Navarro in the last 16.

The British number one served for the first set and forced a decider but went down 6-7 6-3 1-6.

World number one Serena Williams managed to avoid a shock defeat by recovering from a set down to overcome fellow American Sloane Stephens.

The Australian Open champion won 6-7 6-2 6-2 to set-up a quarter-final match against world number 26 Timea Bacsinszky of Switzerland.