Strasbourg, France, 23 May 2015 | AAP/

STRASBOURG, AAP/ – Sam Stosur has advanced to her first final of the year with an impressive three-set win over highly-rated young American Sloane Stephens at the WTA Internationaux de Strasbourg.

In a major morale booster ahead of the French Open starting on Sunday, Stosur rolled Stephens 3-6 6-3 6-0 on Friday.

Her victory came hours after the former French Open finalist was thrust into a likely third-round showdown at Roland Garros with defending champion Maria Sharapova.

In the final, Stosur will face Frenchwoman Kristina Mladenovic, who advanced when compatriot Virginie Razzano retired in the second set with an abdominal strain.

After taking the first set against Stephens, Stosur then built a 3-1 lead, only to lose five games in a row and watch as the American sent the match into a deciding third set.

But she responded in style, allowing Stephens just nine points in a brutal final stanza that she won without the loss of a game.

The Australian moves into her 21st career tour final, and her fifth on clay; her one claycourt title came in Charleston in 2010.

The result this week in Strasbourg marks the first time Stosur has won three matches in a row this season.