Sharapova misses feat

Also advancing were four-time womens winner Serena Williams,defending champion Petra Kvitova and second-seeded Victoria Azarenka,but four-time Grand Slam champion Kim Clijsters lost in what she says is her final Wimbledon before retirement later this year.

The sixth-seeded Williams won the last three games of the final set to beat 65th-ranked wild card Yaroslava Shvedova of Kazakhstan 6-1 2-6 7-5,in cool and gusty conditions on Court 2.

Williams hopped in joy with both feet in the air after hitting a big forehand that forced an error by Shvedova on the first match point,ending a hard-hitting contest that lasted nearly two hours.

I didnt want to lose today and I thought,Just stay relaxed, Williams said. Williams will next face Kvitova,who rallied from a set and a break down to beat former French Open champion Francesca Schiavone 4-6 7-5 6-1 in an error-strewed match on Court 3. The first player to reach the quarters was 37th-ranked Austrian Tamira Paszek,who beat Italys Roberta Vinci 6-2 6-2 to reach the final eight for the second year in a row.

Federer overcomes back trouble

In mens play,six-time champion Roger Federer was the first to reach the quarters,overcoming an early back problem to beat Xavier Malisse 7-6 1 6-1 4-6 6-3 and extend his record for most consecutive Grand Slam final-eight appearances to 33.

Federer said he felt much better after taking a medical timeout and receiving treatment. I feel way better than a few hours ago, Federer said after the match. Honestly,Im not too worried. Ive had bad backs over the years. I just have to keep an eye on it now 8230; I hope Ill be 100 percent on Wednesday.

In a late match under the Centre Court roof,top seed Novak Djokovic sauntered into the quarterfinals with a 6-3 6-1 6-3 demolition of countryman Viktor Troicki. Djokovic came into the encounter on the back of an 11-match winning streak against his opponent and never looked like relinquishing the psychological edge.

After smacking an ace down the middle on her third match point,Lisicki collapsed to her knees and shook both fists. Its just unbelievable, Lisicki said. For the third time Ive beaten the French Open champion here. Im just so happy. Ive lost the three previous meetings against her. Now I just played well and beat her for the first time.

Lisicki will next face fellow German and No. 8 Angelique Kerber,who drubbed Clijsters 6-1 6-1. The 47th-ranked Belgian has said she is retiring after this years US Open. Clijsters,who has been dogged by injuries this year,walked off Court 3 with a brief wave. Third-seeded Agnieszka Radwanska also advanced,beating Italian qualifier Camila Giorgi 6-2 6-3.

Azarenka,the Australian Open champion,routed 14th-seeded Ana Ivanovic 6-1 6-0.