PARIS, Feb 9: Fourth seed Nadia Petrova kept her cool to advance majestically into the semi-finals of the 600,000-dollar WTA Paris Indoor Open here on Friday.

The big-serving world number seven beat her seventh-seeded compatriot Dinara Safina in straight-forward fashion, 6-3, 6-2.

Petrova said the difference was that she more than her opponent had managed to stay calm. “I'm very happy. It was a good quality match. There were a few unforced errors in the beginning but we both wanted to win so much that we were both tense,” said the 24-year-old.

“She's quite a dangerous player but she gets very upset with herself so my point was to try not to show any sense of irritation.”

In Saturday’s semi-final Petrova will face the winner of the last match of the day between home favourite Amelie Mauresmo and Russian eighth seed Anna Chakvetadze. —AFP