( CNN ) -- Maria Sharapova 's bid to end her long wait for a second Wimbledon crown came crashing to a halt on Monday , while Kim Clijsters ' final appearance at the grass-court grand slam also finished in round four . World No . 1 Sharapova lost her rematch with Sabine Lisicki , who she beat in last year 's semifinals before losing the title match . Sharapova won the event as a 17-year-old in 2004 to announce herself as a new star in women 's tennis , but the defeat by Petra Kvitova 12 months ago is the closest she has come to a repeat success in London . German 15th seed Lisicki powered past her Russian opponent to win 6-4 6-3 and set up a last-eight clash with eighth-seeded compatriot Angelique Kerber , who thrashed former No . 1 Clijsters 6-1 6-1 in just 49 minutes . It is the first time that two German women have made it to the second week of the tournament since 1995 , when Steffi Graf won the title for the sixth time and Anke Huber lost in round four . `` It 's just unbelievable . I 'm so happy . I had lost the last three meetings with her , so it 's nice to finally win one , '' said Lisicki , who had lost five matches in a row coming into Wimbledon , including a first-round defeat at the French Open . `` I just went for my shots out there . I felt great , it 's my favorite tournament . I love the crowd and playing on grass . I 'm a fighter and I fight to the last game . I think I 'm getting better with each match . '' Sharapova , who won the French Open last month after losing in January 's Australian Open final , struggled after going 3-1 down in the opening set and a 45-minute rain delay did not help her get back into rhythm . `` She did many things better than I did . She played very well , '' said Sharapova , who saved two match-points . `` I could have done things differently but not on this particular day . '' Four-time grand slam champion Clijsters , who has never got past the semifinals at Wimbledon , could not get going against Kerber -- who fired 19 winners to 10 , and just five unforced errors to the Belgian 's 13 . Clijsters , 29 , will retire for the second time following September 's U.S. Open , a tournament she has won three times . `` I think the first year that I played here , I was here just to take it all in . I do n't even think I was here to play tennis . I needed to just open my eyes and look at everything , '' Clijsters said of her first Wimbledon appearance in 1999 . `` It was such an amazing thing . To me this was like Disneyland to another child . It was such a beautiful thing . '' In the other half of the Wimbledon draw , four-time winner Serena Williams will face defending champion Petra Kvitova in the quarterfinals after both battled through with three-set victories . Williams , seeking her first grand slam title since 2010 , triumphed 6-1 2-6 7-5 against Kazakhstani Yaroslava Shvedova out on Court Two . Shvedova won a record 24 points out of 24 in her first set against French Open runnerup Sara Errani on Saturday , but made a poor start in windy conditions before battling back to level . Williams , bouncing back from her first-round exit at Roland Garros , hit 35 winners to 24 , and made 13 unforced errors to her opponent 's 20 . `` The bottom line is I can play so much better than I am . If I could n't do better that would be a problem , '' Williams said . World No.4 Kvitova has never beaten the American sixth seed , losing both meetings in 2010 at the Australian Open and then the Wimbledon semifinals . The Czech left-hander came from behind against 2010 French Open champion Francesca Schiavone as she beat the Italian 4-6 7-5 6-1 . Schiavone , at 32 the oldest player left in the draw , paid for her 13 double faults and struggled to keep her cool after slipping on the wet grass at the end of the second set . World No . 37 Tamira Paszek reached the quarterfinals for the second year in a row , beating Italian 21st seed Roberta Vinci 6-2 6-2 . The 21-year-old Austrian , who has lost in the first round of five of her last six grand slam appearances , will next face second seed Victoria Azarenka of Belarus . Australian Open champion Azarenka was unaffected by a rain break as the roof was closed on Centre Court as she demolished Serbia 's Ana Ivanovic 6-1 6-0 in a battle of former world No . 1s . Polish third seed Agnieszka Radwanska will feature in the quartefinals for the first time since 2009 after beating 20-year-old Italian qualifier Camila Giorgi 6-2 6-3 . Radwanska , 23 , who also reached the last eight in 2008 , will next play Russian 17th seed Maria Kirilenko -- who beat China 's No . 30 Peng Shuai 6-1 6-7 ( 8-6 ) 6-3 . Kirilenko 's only other grand slam quarterfinal appearance was at the 2010 Australian Open , while Peng is yet to get that far in singles play .
World No . 1 , and the United States is not a signatory to that treaty. Lisicki will next play compatriot Angelique Kerber in Wimbledon quarterfinals . Eighth seed Lisicki beats Kim Clijsters in Belgian 's final appearance at SW19 . Four-time winner Serena Williams to play defending champion Petra Kvitova .