Shaky Sharapova survives to run win streak to 18 straight

The Russian fourth seed, unbeaten since the start of the year,  rallied from 205 down in the first set as she put out the two-time  winner and holder from Slovakia in just under two hours.

 "In the first set I was playing like I didn't even belong on that  court.  I finally got my groove back, and it just felt like, you  know, I finally belonged to be out there.

 "My level just was so low in that first set.  I wasn't going up on  my serve, I wasn't returning.  I was making so many errors," said  Sharapova.

 The reigning Australian Open champion, will face a semi-final  against Russian second seed Svetlana Kuznetsova, who beat Polish  10th seed Agnieszka Radwanska 6-2, 6-4.

 The Russian has lost only one set so far during the event. "I played better first set, but in the second she played a little bit better, and I missed few," said Kuznetsova.

 "Im confident playing out there. It was good win for me after playing her in Australian Open (third round loss)."

 Sharapova leads the series against her compatriot 4-3 winning the  pair's last two matches.

 Men's number two Rafael Nadal and third seed Novak Djokovic reached  the quarter-finals, joined by top seed Roger Federer as he beat  Croatian Ivan Ljubicic for the 11th time on hardcourt 6-3, 6-4.

 Nadal won a grudge battle with Jo-Wilfried Tsonga, beating the  Australian Open finalist 6-7 (4-7), 7-6 (7-3), 7-5. Djokovic, last  year's losing finalist to the Spaniard, had an easier time over  Guillermo Canas 6-2, 6-3.

 "It was not revenge, not a special match, but this was an important  win for me," said Nadal. "He's going to be one of the rivals for  this year.

 "These matches are very important always."

 A three-hour, three-minute struggle with a comeback from 5-2 down  in the final set brought Nadal full circle over Tsonga after losing  a Melbourne semi-final to the breakout Frenchman two months ago.

 Tsonga served for victory leading 5-3 in the final set, a double- fault and a forehand unforced error to lose the game keeping Nadal  in the chase.

 Another break of Tsonga for 6-5 put the three-time Roland Garros winner in the driving seat, with Nadal closing out the tight victory on the first of three match points a game later.

 "The ball and the court is a little bit different here," said  Nadal. "There's a lot more topspin than in Australia, so that helped  me a little bit.

 "I played better today than in Australia, but the conditions are  better here for me."

 Djokovic called himself "very happy to finish in straight sets,"  against Canas. "Guillermo is a very tough opponent.  He runs lot and  he gives a lot of balls back.

 "I needed to be aggressive and just play my game and just try  to finish the point as soon as possible but be patient at the same  time."

  Argentine seventh seed David Nalbandian reached the last eight as he dispatched Spaniard Juan Carlos Ferrero 6-2, 6-2. Swiss Stanislas Wawrinka defeated Lee Hyung-taik of South Korea 6-1, 5-7, 6-4.

 Resurgent German Tommy Haas stunned Scot Andy Murray, seeded 11th,  2-6, 7-5, 6-3.