[Rusty Backhand]

NEW YORK, Sept 6 (Reuters) - Top seed Maria Sharapova turned up the power in the third set and survived her toughest test, turning back the challenge of fellow-Russian Nadia Petrova 7-5 4-6 6-4 on Tuesday to reach the U.S. Open semifinals.

http://go.reuters.co.uk/newsArticle.jhtml?type=tennisNews&storyID=9578837&section=news&src=rss/uk/tennisNews