Sharapova vows to make clay mark in Paris

Maria Sharapova has vowed to put years of claycourt under-achievement behind her, starting with victory over German 15th seed Andrea Petkovic in Wednesday's French Open quarter finals.

Sharapova, the seventh seed, has tasted success at Wimbledon (2004), the US Open (2006) and the Australian Open (2008), but her best Roland Garros showing remains a straight sets semi final defeat by Ana Ivanovic in 2007.

The former world number one is a different prospect on clay these days, however, and demonstrated her newly acquired ease on the dirt by triumphing at the Rome Masters earlier this month.

With the top three seeds already eliminated at Roland Garros, Sharapova will also know that this year's tournament may represent her best ever chance of becoming the 10th woman to complete a career Grand Slam.

"I've always said it would be challenging to win here but I've always worked hard on preparing myself as best as I could," said Sharapova, after a 7-6 (7/4), 7-5 defeat of Polish 12th seed Agnieszka Radwanska in round four.

"Physically, and mentally; knowing that you have to be more patient here than maybe at other points in other tournaments.

"It's just going out there and believing in what you've done before and what you've prepared."

Sharapova has a 3-1 win-loss record against Petkovic, who stunned the Russian in straight sets in the last 16 at this year's Australian Open before Sharapova gained her revenge in the semi finals of the Miami Masters.

"We played in Melbourne and then in Miami, a month or so ago," said Sharapova.

"She's a very tough opponent. She's also quite good on this surface and moves well, and she'll use that to her advantage. It'll be tough but I'll go out and try to win that match."

Petkovic's 6-2, 2-6, 6-4 victory over Russian 25th seed Maria Kirilenko equalled her best Grand Slam performance, following her run to the last eight in Melbourne.

A win over Sharapova would take her into the last four at a major for the very first time, but the 23-year-old world number 12 said she was simply thrilled to be moving in such exalted circles.

"Any quarter final in a Grand Slam is going to be a test," said Petkovic, who won her second career singles title at Strasbourg earlier this month."

"I've played her (Sharapova) twice this year already. She's a great champion and I admire her a lot, both as an athlete and how she handles herself."

"I think she represents women's tennis really well. I feel honoured to be in the quarter finals at all and even more so playing such a champion."

"I'll have to play my best claycourt tennis to beat her."

Wednesday's other quarter final pits Belarusian fourth seed Victoria Azarenka against Chinese sixth seed Li Na, the first player from her country to reach the last eight at Roland Garros.

Azarenka, the top-ranked player left in the draw, beat Russia's Ekaterina Makarova 6-2, 6-3 in the fourth round, while Li laboured to a 2-6, 6-1, 6-3 defeat of Czech ninth seed Petra Kvitova.

Azarenka has beaten Li just once in four attempts, most recently losing in the last 16 at the Australian Open, and has never gone beyond the quarter finals at a Grand Slam.

"I'm in a different chapter of my career," said Azarenka.

"It's going to be a different quarter final for me. But I'm feeling really confident and I'm really looking forward to it."