(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 don'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 couldn'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.