Maria Sharapova is the new world number one.

The Russian eased to a 6-3, 6-3 victory over Wimbledon champion Petra Kvitova to move into the French Open final, where she will meet Sara Errani.

Sharapova, looking to complete a career Grand Slam with victory at Roland Garros, was the more assured player with Kvitova, never really comfortable on the red clay, faltering at key moments.

The world number one position is a culmination of a lot of hard work for Sharapova, who missed a year due to a shoulder injury between 2008-09. "It's a long road back. It's a long process. It's a lot of days of frustration and uncertainty, not knowing if you'll ever get there, not knowing how much you want it, not knowing whether there would be a moment like that for you again," Sharapova said after the match.

"So there is definitely a lot of tough things you have to go through to get to this point, but it's all really worth it.

"I have played tennis since I was four years old. I committed myself to this sport. I've always loved what I did. When it was taken away from me for a while, that's when I realised how grateful I was and how lucky I was to be playing it."

Sharapova will face Italian Errani, who saw off the challenge of US Open champion Samantha Stosur 7-5, 1-6, 6-3. Errani, will also play the women's double final with partner Roberta Vinci and will face another Russian test against Maria Kirilenko and Nadia Petrova.

"Quarterfinals, semi-finals, I have not been thinking about the results, just playing the matches one by one, but this is incredible," Errani said.

"I didn't expect it, and I'm here. So I don't know what to say. For the match, I think it was very difficult. It's not (finished), so I have one match more. I have to think about that."

Stosur, understandably, was disappointed. "My own expectation probably does far exceed anyone else's. I think I am capable of doing more, and that's probably why it's so disappointing when you don't do it."