* Women's second seed Azarenka withdraws injured
* Nadal's conqueror Darcis pulls out with shoulder problem
* Tsonga retires injured, local hope Murray marches on
* Tournament over early for seven players on Wednesday (Refiles to correct Tsonga's seeding)
By Martyn Herman
LONDON, June 26 (Reuters) - Wimbledon king Roger Federer and Maria Sharapova endured jolting second-round losses to opponents outside the world top 100 in a freakishly dramatic 'Wednesday Wipeout' that saw seven players withdraw injured and the draw shredded.
Second seed Victoria Azarenka, Frenchman Jo-Wilfried Tsonga and even Steve Darcis, man-of-the-moment after his opening day victory over Spaniard Rafa Nadal, were among the casualties as the medical bulletins piled up.
With title contenders dropping like flies, some before even striking a ball in anger, home favourite Andy Murray must be licking his lips after avoiding the scrapheap with an incident-free second round win over Taiwan's Lu Yen-Hsun.
Murray's hopes of emerging as "last man standing" to claim his first Wimbledon crown on Sunday week have soared after two rounds which have culled Nadal, Federer and sixth seed Tsonga from his half of the draw.
After a day of slips and slides, strained shoulders and aching knees, seven-times champion Federer was expected to glide serenely above the mayhem around him when he stepped out on Centre Court to play Ukraine's Sergiy Stakhovsky.
Three hours later on what former champion John McEnroe called "the craziest day ever" the Swiss great's dream of an eighth title was over.
Playing old-school serve and volley tennis the like of which was supposed to have gone out of fashion, the 27-year-old world No.116 won 6-7(5) 7-6(5) 7-5 7-6(5) to snap third seed Federer's streak of reaching 36 consecutive grand slam quarter-finals.
"I'm still in disbelief," Stakhovsky said. "I played the best tennis I have ever played. When you play Roger Federer it's like your're playing two persons.
"First you play Roger Federer, then you play his ego. I couldn't play any better today. It was a fantastic day for me."
For once, Federer's box of tricks could not rescue him and there was an "end of era" feel as the 31-year-old walked into the Centre Court shadows to a standing ovation.
"It's normal that after all of a sudden losing early after being in the quarters 36 times, people feel it's different," Federer, who suffered his earliest Wimbledon defeat since a first-round loss in 2002, defiantly told a news conference.
"Usually I do turnarounds pretty good. I'm looking forward to what's to come. I hope I can play a good summer."
Nadal's first round defeat by Darcis on Monday created shockwaves but Wednesday's seismic events went off the scale.
Ten seeds perished and the seven players to withdraw or retire mid-match was record for a single day at a grand slam.
Croatian 10th seed Marin Cilic, who could not take to the court to play France's Kenny De Schepper after a knee injury flared up, described Wednesday as a "very black day".
Third-seed Sharapova was sent across the grounds to the bowl-like Court Two to face Portuguese firebrand Michelle Larcher de Brito and found the 131st-ranked qualifier too hot to handle as she slipped and slid to a 6-3 6-4 defeat.
Sharapova needed a 10-minute injury timeout after one of several falls left her clutching her hip and at one stage was overheard describing the court surface as "dangerous."
"I don't think I've ever fallen three times in a match before in my career, so that was a little strange," the Russian former champion told reporters.
Women's ninth seed Caroline Wozniacki also fell heavily on Court Two in her defeat by Czech Petra Cetkovska while second seed Azarenka did not even start against Italy's Flavia Pennetta due to the knee injury she suffered in a first-round tumble.
"I don't know if it's the court or the weather," the Belarussian told reporters. "I can't figure it out it.
"Would be great if the club or somebody who takes care of the courts would examine (it)."
A tournament spokesman said "the surfaces at the start are always lusher than at the end," while three-times former champion Boris Becker added "grass is always going to be slippery in the first couple of matches, that has been the case for the past 100 plus years."
Tsonga did not blame the surface for a knee injury that forced him to stop against Latvian Ernests Gulbis while Czech veteran Radek Stepanek also had to quit with a hamstring injury while trailing Poland's Jerzey Janowicz.
Spare a thought for Darcis.
Two days after easily the biggest win of his career over Nadal, the 29-year-old's tournament ended with a whimper as the shoulder he hurt in a fall against the Spaniard made it too painful to face Poland's Lukasz Kubot.
Even American marathon man John Isner was struck down.
The 18th seed played 183 games to beat Nicolas Mahut in a record-breaking epic in 2010 but lasted only two before his knee buckled and he quit against Frenchman Adrian Mannarino.
Kazakh Yaraslava Shvedova handed 2011 Wimbledon women's champion Petra Kvitova a walkover, meaning the Czech eighth seed is the highest-ranked player left in the rubble of the bottom half of the draw.
The lower half of the men's draw was supposed to have been the one to avoid but with Federer, Nadal, Tsonga and Isner all gone, "Murray Mania" is cranking up with home fans salivating at the prospect of him emulating Fred Perry's 1936 title.
The world number two has not dropped a set so far and with Spain's Nicolas Almagro, seeded 15, the next highest-ranked survivor in his half the route to the latter rounds suddenly looks an enticing one for last year's runner-up.
However, Wednesday proved just how unpredictable tennis can be and the Scot is not counting his chickens.
"That's sport," he said of a chaotic day. "You can fall down the stairs, trip over your shoelaces. Who knows? But I feel fine right now," said Murray whose next opponent is Tommy Robredo. (Reporting by Martyn Herman; editing by Ken Ferris)