Sam Stosur makes light work of Nadia Petrova

US Open champion Sam Stosur has progressed to the fourth round of the French Open after a straight-sets victory over Russian Nadia Petrova.

In the opening set both women broke each other's serves before Australian Stosur broke again and went on to take the set 6-3.

Stosur had just one chance to break in the second and took it before edging out Petrova in what was quite an even match on Court 1 at Roland Garros.

Stosur, 28, will take on unseeded American Sloane Stephens in the fourth round after she defeated home favourite Mathilde Johansson earlier today.