LONDON -- Serena Williams joined a growing list of marquee names eliminated early at this wild and unpredictable Wimbledon.
The defending champion and five-time Wimbledon winner failed to close out a see-saw third set Monday, dropping the last four games to Sabine Lisicki of Germany and losing 6-2, 1-6, 6-4 in the fourth round. The result ended Williams' career-best 34-match winning streak.
It was the latest in a string of improbable exits to jolt the tournament, with defending champion Roger Federer and Rafael Nadal knocked out in the first three days along with Maria Sharapova and Victoria Azarenka.
"I probably couldn't be more disappointed," Williams said. "I think I may have backed off of a success. I was playing something successful. I didn't continue that path. The result didn't go the way it could have gone had I continued to play the way I did in the second set."
Her loss left top-ranked Novak Djokovic and No. 2 Andy Murray as the only pre-tournament favorites still standing.
Those two stayed on course for a meeting in the final by winning in straight sets on Centre Court. Djokovic ousted German veteran Tommy Haas after Murray beat Mikhail Youzhny of Russia. Neither player has dropped a set en route to the quarters.
Williams hadn't either before this match. But after dropping the first against Lisicki, she won nine straight games to lead 3-0 in the third. The players then traded breaks to give Williams a 4-2 lead, but the American couldn't win another game despite having four break points at 4-3.
Lisicki converted her second match point with a forehand winner.
"I'm still shaking," Lisicki said in a post-match interview, covering her face with her hands to wipe away tears. "I'm just so happy."
Williams said her serve -- usually her main weapon -- let her down in the third set.
"I felt that I was on the verge of winning," she said. "At that point I just was physically unable to hold serve. ... You have to be ready and willing to hold your serve. I wasn't willing or able, probably didn't even want to hold my serve today."
Lisicki reached the semifinals at the All England Club in 2011 but this will rank as her biggest victory at the grass-court Grand Slam. She has eliminated the reigning French Open champion the last four times she played Wimbledon, having missed the tournament in 2010. She ousted Sharapova in the fourth round last year.
Djokovic reached his 17th straight Grand Slam quarterfinal by beating Haas 6-1, 6-4, 7-6 (4). He failed to serve out the match at 5-3 in the third and wasted a match point in the next game before closing out the tiebreaker with a forehand winner on his fourth match point.
"I think that I'm playing really, really good tennis at this moment," Djokovic said. "Maybe even better than back in 2011 when I won this tournament."
Djokovic moved on to No. 7 Tomas Berdych, who reached his first Wimbledon quarterfinal since he was the runner-up in 2010 by beating Bernard Tomic 7-6 (4), 6-7 (5), 6-4, 6-4. Berdych beat Djokovic in the semifinals that year.
Djokovic's quarterfinal streak is the third longest behind Roger Federer's 36 and Jimmy Connors' 27. Federer's string ended with last week's loss in the second round.
Murray, facing the ever-increasing pressure to become the first British man since 1936 to win Wimbledon, was in trouble in the second set. He trailed 5-2 against Youzhny, who was a 2012 Wimbledon quarterfinalist, but broke back when the Russian served for the set at 5-4. Then, down 5-3 in the tiebreaker, Murray took the set's last four points. He broke immediately in the third, and cruised from there to set up a match with Fernando Verdasco of Spain.
Murray is the only British player left in the tournament, after Laura Robson lost. She couldn't recover from her missed chances in the first set and fell 7-6 (5), 7-5 to Kaia Kanepi of Estonia, failing to become the first British woman in the quarters of any Grand Slam since 1984.
Robson, the first British woman to reach the second week at Wimbledon since 1998, squandered a chance for a headline matchup with Williams. Instead, Kanepi will face Lisicki in the quarterfinals.
Former champion Petra Kvitova, last year's runner-up Agnieszka Radwanska and No. 4 David Ferrer all avoided upsets to advance, as did sixth-seeded Li Na of China.
Juan Martin del Potro, playing with his left knee heavily taped after a scary fall in the previous round, beat Andreas Seppi 6-4, 7-6 (2), 6-3. He said his knee was "really painful" and he hopes it will be better by the time he plays Ferrer on Wednesday. Ferrer overcame another slow start to beat Ivan Dodig of Croatia 6-7 (3), 7-6 (6), 6-1, 6-1.
Despite Williams' loss, there's still an American woman in the quarters after Sloane Stephens beat 19-year-old Monica Puig of Puerto Rico 4-6, 7-5, 6-1.
On a busy day at Wimbledon with every round-of-16 match to be played, Kvitova was the first to reach the last eight, beating Carla Suarez Navarro of Spain 7-6 (5), 6-3. She will play Kirsten Flipkens of Belgium, who reached her first career Grand Slam quarterfinal by ousting Flavia Pennetta of Italy 7-6 (2), 6-3 -- a year after her ranking plummeted to 262nd because of injuries.
Poland will send two men into the quarterfinals for the first time after 24th-seeded Jerzy Janowicz and 130th-ranked Lukasz Kubot each won five-set matches.
The big-serving Janowicz outlasted Jurgen Melzer 3-6, 7-6 (1), 6-4, 4-6, 6-4, while Kubot defeated Adrian Mannarino 4-6, 6-3, 3-6, 6-3, 6-4. They'll play each other Wednesday with the winner becoming the country's first male Grand Slam semifinalist.
In other matchups, Li faces Radwanska, and Stephens plays 2007 finalist Marion Bartoli.