Updated

By Simon Cambers

NEW YORK (Reuters) - Australian Sam Stosur extended her best-ever run at the U.S. Open by reaching the fourth round on Friday and then said she now feels like she belongs among the game's elite.

The fifth seed had never been beyond round two in New York but turned in an impressive display to beat Italy's Sara Errani 6-2 6-3 in just one hour 20 minutes.

The 26-year-old Stosur said reaching her first grand slam final at the French Open in June has done wonders for her confidence and feels there was no reason she could not go all the way at Flushing Meadows.

"Once you get to this point, you never know what can happen," Stosur told reporters. "So if you keep playing well, you can find yourself in maybe the semis or finals. If I've been there once, I definitely want to try to be there again.

"I think I've had a pretty consistent year and now to be in the fourth round here is a big jump. It's pleasing to now back it up in another grand slam and to be playing well.

Stosur broke into the world's top 10 for the first time in March but missed the two main U.S. Open warm-up tournaments in Cincinnati and Montreal because of an injury to her right arm.

But since returning in New Haven last week, she has been pain-free and, apart from the moment when she was broken once in the second set, was in total command against Errani.

The break was a momentary blip because from 3-2 down Stosur won four straight games to seal victory and a meeting with 12th seed Daniela Hantuchova.

"We've had some good matches in the past," she said. "I think it's going to be whoever can execute their game-plan better on the day.

"But I know what I'm going to want to do against her. If I can do that, I think I have a chance."

(Editing by Frank Pingue)