Intro:

Nadia Petrova and Maria Sharapova are through to the fourth round of the BNP Paribas Open after their respective victories over Samantha Storsur and Simona Halep.

Script:

Samantha Stosur was the big casualty in the third round of the BNP Paribas Open on Monday after being knocked out by Nadia Petrova.

Stosur had trouble overcoming Petrova on her way to winning the US Open last year and dropped the first set 6-1 before having to battle back in the second from 3-1 down.

Having also saved a match point Stosur took the second set on the tie break.

However, Petrova wasn't to be denied and after moving 4-2 ahead in the decider eventually won the match 6-1, 6-7 (6), 7-6 (5) after Stosur missed a forehand.

Elsewhere, former champion Maria Sharapova made light work of Simona Halep, taking the first set 6-3.

The number two seed then raced into a 5-1 lead in the second set before Halep battled back, only for Sharapova to close out the match 6-3, 6-4.

Sharapova will face Roberta Vinci in the next round at Indian Wells.