Serena is latest seed to wither

Serena Williams became the latest victim of this year's Wimbledon giant-killings as the world number one slumped to a stunning 6-2, 1-6, 6-4 defeat against German 23rd seed Sabine Lisicki in the fourth round yesterday.

Williams followed second seed Victoria Azarenka and world number three Maria Sharapova out of the women's tournament, while defending champion Roger Federer and two-time Wimbledon winner Rafael Nadal suffered shock exits from the men's draw last week.

Since an embarrassing first-round loss against Virginie Razzano at last year's French Open, Williams had won 77 of her 80 matches, collecting the Wimbledon, US Open, French Open and Olympic titles in the process.

The 31-year-old, a 16-time Grand Slam champion, had swept through the first week, dropping just 11 games in her first three matches to extend her winning run to 34 matches, but she had no answer to Lisicki's big serve and booming ground-strokes.

"I'm still shaking, I'm so happy," said Lisicki, breaking into tears.

"Serena played a fantastic match. She's such a tough opponent and it's just an amazing feeling to win." Serena felt she let victory slip away, saying: "I definitely made too many errors, but she was playing with nothing to lose. When you play with such freedom this kind of thing can happen."

Lisicki, a semi-finalist in 2011 who has never been past the fourth round at any other Grand Slam, will play Estonia's Kaia Kanepi for a place in the last four.

Kanepi had shattered Britain's dreams of a first woman in the Wimbledon quarter-finals for 29 years, beating unseeded teenager Laura Robson 7-6 (8), 7-5.

Former champion Petra Kvitova booked her fourth consecutive Wimbledon quarter-final appearance with a 7-6 (5), 6-3 win over Spain's Carla Suarez Navarro.

Czech eighth seed Kvitova, who won Wimbledon in 2011, overpowered Spanish 19th seed Suarez Navarro with 23 winners and will face Belgian 20th seed Kirsten Flipkens for a place in the semi-finals.

As the highest seed remaining in the bottom half of the draw, Kvitova has a golden opportunity to reach her second Grand Slam final.

"I was pretty nervous today. There's a bit more pressure because everyone expects me to win," Kvitova said.

Flipkens, the 2003 junior champion, sealed her first Grand Slam quarter-final berth with a 7-6 (2), 6-3 victory against Italian veteran Flavia Pennetta.

Chinese sixth seed Li Na raced into the quarter-finals with a 6-2, 6-0 demolition of Italian 11th seed Roberta Vinci.

Next up for Li is Polish fourth seed Agnieszka Radwanska, last year's runner-up, who is now the highest-ranked player left after a 4-6, 6-3, 6-3 win against Bulgaria's Tsvetana Pironkova.

American 17th seed Sloane Stephens reached her first quarter-final after battling back to beat Puerto Rico's Monica Puig 4-6, 7-5, 6-1 Stephens, 20, next faces French 15th seed Marion Bartoli, the runner-up in 2007, who cruised to a 6-2, 6-3 win against Karin Knapp of Italy.

In the men's draw Andy Murray kept the British flag flying, beating Mikhail Youzhny of Russia 6-4, 7-6 (5), 6-1 to reach the quarterfinals, where he will play Fernando Verdasco of Spain.