LONDON - Maria Sharapova became the highest profile victim of Wimbledon's black Wednesday as Victoria Azarenka, Steve Darcis, the conqueror of Rafael Nadal, and Jo-Wilfried Tsonga were among seven players forced out with injury. Sharapova, the third seed and 2004 champion, slumped to a shock 6-3, 6-4 defeat to Portuguese qualifier Michelle Larcher De Brito, the world 131.

Her defeat out on Court Two came after she fell to the ground on three occasions and needed a medical timeout to treat a painful left hip. The Russian's dramatic loss came on a day when there was a Grand Slam record seven withdrawals either through retirements or walkovers. That could have been nine had Sharapova given up or even Caroline Wozniacki, a former fellow number one, had surrendered to an ankle injury picked up in her loss to Czech qualifier Petra Cetkovska also on the troublesome Court Two.

"I don't think I've ever fallen three times in a match before in my career, so that was a little strange," admitted Sharapova who was heard on the TV monitors telling umpire Alison Hughes that the court was dangerous. "Well, after I buckled my knee three times, that's obviously my first reaction." World number two and Australian Open champion Azarenka withdrew just minutes before she was due on Centre Court to face Italian veteran Flavia Pennetta for a place in the third round.

A right knee injury, suffered in a fall during her first round win over Maria Joao Koehler on Monday, put paid to her hopes after an MRI scan showed extensive bruising to the knee. French sixth seed Tsonga quit his match with Latvia's Ernests Gulbis with a knee injury at the end of the third set. Also withdrawing were Darcis, Croatian 10th seed Cilic and Kazakhstan's Yaroslava Shvedova.

John Isner and Radek Stepanek both quit during their second round matches. Azarenka's fall happened on Court One, the same arena where Darcis fell and hurt his right shoulder in his defeat of Nadal. "The court was not in a very good condition My opponent fell twice; I fell badly; there were some other people who fell after," said Azarenka, a semi-finalist in the last two years.

On Centre Court, Tsonga needed a medical time-out to have his left knee taped just after he had dropped the second set, 6-3, against world number 39 Gulbis. Tsonga had won the first set, 6-3. But when he dropped the third set 6-3, he gave up. An All England Club spokesman told AFP: "The courts have been prepared in exactly the same way as they have done in the past. There is no change. It is the same seed, everything is identical."

 Darcis, the world number 135, admitted he was devastated. "Not to go on the court today, it's the biggest disappointment I have had," he said. America's John Isner, famous for winning the longest match in history at Wimbledon in 2010, pulled out after just two games of his second round tie against France's Adrian Mannarino with a knee problem.

Croatian 10th seed Cilic then joined the list of walking wounded when he withdrew with a left knee injury. "It's a very black day," said Cilic. Czech veteran Stepanek was also struck down by injury. At 6-2, 5-3 down to Poland's Jerzy Janowicz, the 24th seed, he quit with a left hamstring injury. Shvedova had an arm injury and her withdrawal meant that 2011 champions Petra Kvitova received a free pass into the third round.

Meanwhile, Murray emerged unscathed as the world number two eased into the third round with a 6-3, 6-3, 7-5 win over Taiwan's Lu Yen-Hsun. Tsonga and Cilic were Murray's most likely quarter-final opponents, but instead the highest ranked player left in the Scot's quarter is now Russian 20th seed Mikhail Youzhny. Murray hit 41 winners and served 11 aces to set up a last 32 clash with Spanish 32nd seed Tommy Robredo.

"I thought I kept my concentration well on serve and gave him very few opportunities after the first set," Murray said.

Later Wednesday, defending champion Roger Federer, bidding to become the first man to win the title eight times, tackles Ukraine's Sergiy Stakhovsky. Two former world number ones were knocked out. Lleyton Hewitt was dumped out by German qualifier Dustin Brown, the dreadlocked former Jamaica player winning 6-4, 6-4, 6-7 (3/7), 6-2 Ana Ivanovic was knocked out by Canada's Eugenie Bouchard, the reigning Wimbledon girls' champion, 6-3, 6-3.