|Bartoli, right, will meet German Sabine Lisicki in the quarter-finals after defeating the champion [AFP]
Serena Williams' comeback was ended by Marion Bartoli as the defending champion was beaten in straight sets in the fourth round at Wimbledon.
French ninth seed Marion Bartoli downed the American 6-3, 7-6 to set up a quarter-final with Germany's Sabine Lisicki.
Serena, seeded seventh after serious health problems, struggled throughout against the ninth-seeded Frenchwoman, making a succession of unforced errors on Court One.
Bartoli took the first set on her sixth set point and she continued to move the 13-times Grand Slam champion ruthlessly around the court to move to the brink of victory.
She had three match-points in the 12th game of the second set but Williams showed all her battling qualities and great composure to save them and force a tiebreak.
Bartoli continued to serve strongly and she earned another two match points, the first of which Williams saved with an ace, but the Frenchwoman took the second to take the tiebreak 8-6.
'Dream come true'
"Beating Serena is a dream come true, she is one of the greatest champions of the open era," Bartoli said in a televised interview.
"It was not easy mentally but I did it and I am very happy. She is very imposing.
|Tomic: into the quarters [GALLO/GETTY]
"If you look at her it is difficult to handle the pressure so I was just trying to focus on my own game."
In the men's on Monday, Britain's Andy Murray beat Richard Gasquet in straight sets.
The fourth seed, watched from the Centre Court royal box by Prince William and the Duchess of Cambridge, Kate Middleton, expertly dealt with the considerable threat of the Frenchman to win 7-6, 6-3, 6-2.
Murray clinically took his chances in the warm sunshine while 17th seed Gasquet, who took the Scot to five sets at the grass-court Grand Slam in 2008, squandered the few opportunities he had.
One of unseeded duo Lukasz Kubot or Feliciano Lopez await in the last eight.
Teenage Australian Bernard Tomic followed up his giant-slaying of Robin Soderling as he beat beat Xavier Malisse of Belgium 6-1, 7-5, 6-4.
Earlier, former champion Maria Sharapova overpowered Peng Shuai 6-4, 6-2.
The Russian fifth seed had a few early problems against the unorthodox Chinese before striding away to the last eight on the lawns for the first time since 2006.
The 2004 champion had to save two break points as the opening two games took nearly 15 minutes and her forehand and serve were both a little hit-or-miss.
Peng, who hits double-handed off both sides, threatened again with Sharapova serving at 3-4 but the blonde ramped up the volume and the power on her bludgeoning forehand to stay on level terms then broke through in the next game.
Peng, playing in the fourth round of Wimbledon for the first time, panicked, going down 0-40 and although a couple of beefy serves clawed back two of the break points Sharapova pounced on the third when her opponent made a mess of a forehand she was forced to play one-handed.
Sharapova served out the set to love with an ace and there was sense of inevitability about the rest of the match as she eased through the second set.
The Florida-based 24-year-old, still to drop a set at the championships this year, will face Dominika Cibulkova in the last eight.