French Open: Maria Sharapova and Li Na make semi-finals

Maria Sharapova stormed into the semi-finals of the French Open with a 6-0 6-3 drubbing of Andrea Petkovic.

Sharapova, the Russian seventh seed, rallied from 0-40 down to break in the first game and breezed through the opening set in 32 minutes.

Germany's Petkovic, the 15th seed, broke twice in the second set but Sharapova wrapped up an emphatic win.

Sharapova will meet Li Na in the last four after the Chinese beat fourth seed Victoria Azarenka 7-5 6-2.

Sharapova is looking to complete a career Grand Slam, having won the other three major tournaments once apiece.

And the Russian's ruthless display on Court Suzanne Lenglen suggests she has put her shoulder and elbow injuries behind her and is ready to claim her first Slam title since the 2008 Australian Open.

After losing the first three points of the match, she unleashed a succession of fierce ground strokes to blaze through the first set without losing a game.

Petkovic, who beat Sharapova in the 2011 Australian Open fourth round, finally got on the board in the third game of the second set and followed up with her first service break to level at 2-2.

She kept parity until 3-3, but could not hold Sharapova back for long, and the 2004 Wimbledon champion charged through the next three games to round off a 91-minute triumph.

"It was tougher than the scoreline suggests," said Sharapova. "There were a lot of games that could have gone either way. I played really smart on the important points.

"There is no doubt I have improved on this surface. As the years have gone on I feel I have got better and better.

"I feel physically I have overcome many challenges that maybe a few years ago would have been tough for me.

"I'm in the semi-finals and my goal is just to take it a step further right now. I put a lot of work in to be at this stage of the grand slams. I'm really happy that it's here."

Li Na became the first Chinese player to reach the French Open semi-finals

Li, meanwhile, is through to the last four at Roland Garros for the first time after dismantling Belarusian Azarenka, who was the highest seed remaining in the women's competition.

Australian Open runner-up Li broke serve in the 12th game to pocket the opening set on Court Philippe Chatrier.

She broke Azarenka's serve again to take a 4-2 lead in the second and sealed the win on her opponent's serve by converting her third match point.

Li, who has never won a clay court title on the WTA tour, said the result sent out a message to those who had doubted her ability to reproduce her hard court prowess on the slower surface.

"Many people think I'm not so good on a clay court, but I think now they should change their minds a little bit," she said.

"You have to slide a lot and you have to play a lot of topspin, and Asian players like to hit flat. But after this I think all Asian people should have more confidence playing on clay."

Azarenka, 21, who has lost all four of her Grand Slam quarter-finals, said: "She was the better player today. She played very well in the important moments.

"I don't think I was playing my best tennis but I was really fighting hard and trying to get the momentum going. It just didn't happen today.

"But I had opportunities in the first set. It was really close. I just wasn't disciplined enough to take them."