(Releads with Plushenko, adds quotes, medals)
* Home figure skating hero Plushenko pulls out with injury
* News overshadows men's hockey competition
* Skiers wear sleeveless tops as temperatures rise
* Anti-corruption activist criticises Games
* Worker breaks legs after being hit by bobsleigh
By Mike Collett-White
SOCHI, Russia, Feb 13 (Reuters) - Russia's flamboyant figure skater Yevgeny Plushenko pulled out of the Winter Olympics through injury on Thursday in a development that immediately deflated home fans pumped up by an opening victory for their beloved men's ice hockey team.
At the Iceberg Skating Palace, there was disbelief when the announcement was made over the public address system that the 31-year-old would not compete in the men's individual figure skating event after he pulled up injured during his warm-up.
The news came seconds before Plushenko was due to start his short programme, and left a stunned audience wondering if they had witnessed the end of a glittering career.
Plushenko, a controversial selection for the Games after a lack of competitive action in the build-up, won his fourth Olympic medal on Sunday when he helped Russia triumph in the inaugural team competition, but during his warmup routine he repeatedly clutched his back.
"I came out for the warm-up... and in the first triple Axel I stepped out and felt like I had a knife in my back," he told reporters.
"And the second triple Axel, it was a horrible one. It was a hard landing and after this I didn't feel my right leg. I took four painkillers and it didn't help. I think it was God saying, 'Yevgeny, enough is enough'."
A few hundred metres away at the futuristic Bolshoy Ice Dome, the mood could not have been more different.
More than 10,000 flag-waving Russian fans roared the men in red to a somewhat laboured 5-2 win over Slovenia, underlining the sport's popularity in Russia and how dearly the home nation would love to win the final held on the last day of the Games.
As ice hockey mania swept Sochi, the United States laid down a marker by thumping Slovakia 7-1, and Canada were opening the defence of their title against Norway in the late game.
The news of Plushenko's withdrawal, on the sixth full day of competition, took some of the gloss off a day when six medals were decided.
U.S. CLEAN SWEEP, SLUSHY SNOW
In the mountains, Joss Christensen of the United States won the inaugural men's freestyle skiing slopestyle.
Gus Kenworthy took silver and Nick Goepper the bronze in a U.S. podium sweep, taking pressure off a team that some domestic media had begun to question as it languished down the medals leaderboard.
"I am shocked. I am stoked to be up here with my friends. America, we did it!" said Christensen, after another bumper crowd at the Extreme Park saw the skiers push their acrobatic routines to the limits.
In the women's cross-country 10km classic, several athletes wore sleeveless tops as temperatures touched 13C in bright sunshine and contestants complained of tough conditions.
Poland's Justyna Kowalczyk powered to victory, but Russian Natalia Zhukova, who finished seventh, told reporters: "It's the first time of my life I've raced in such warm weather."
In the latest weather-related disruption, practice for the men's freestyle skiing aerials event was cancelled because of unseasonably high temperatures.
But organisers played down concerns about the quality of the snow that many athletes have described as slushy and difficult, and which may explain some of the crashes in disciplines ranging from slopestyle to cross country.
"It is a constant battle for winter sports," said Mark Adams, International Olympic Committee spokesman. "We are relaxed but we watch the situation."
Also in the mountains, France's Martin Fourcade won the men's biathlon 20km individual title, his second gold of the Games.
Back in Sochi, Li Jianrou avoided an early pile-up to win the women's 500 metres short track speed skating, extending China's winning streak at the distance to a fourth Winter Games.
The 27-year-old first-time Olympian described it as "a miracle".
Compatriot Zhang Hong claimed the women's 1,000m speed skating title at the Adler Arena, beating pre-race favourites Heather Richardson and Brittany Bowe of the United States.
In the sliding disciplines, a track worker was struck by a bobsleigh and suffered two broken legs during a practice session, IOC President Thomas Bach told Reuters.
In the last event of the day, the inaugural team relay went to luge powerhouse Germany, making it a clean sweep of all four luge gold medals at the Sochi Olympics.
Germany are top of the medals table with seven golds, ahead of Canada, Norway, the Netherlands and the United States, all on four. Russia are seventh with two.
DREAMING OF HOCKEY GOLD
For Russian President Vladimir Putin, who has staked his legacy on holding a successful Games, the ultimate sporting dream would be the men's ice hockey gold and hosts' pool match against the United States on Saturday has stirred memories of the "Miracle on Ice" at the 1980 Lake Placid Games.
Thirty-four years ago, a group of American college players beat the then Soviet Union's "Big Red Machine" 4-3 in a mismatch of David and Goliath proportions en route to a highly unlikely gold.
The Cold War climate that then prevailed may have thawed, but Putin has conjured the frosty relations of the time to attack Western criticism of his human rights record, and allegations of corruption connected with the Games, which have marred the buildup.
Putin has dismissed charges of widespread corruption, which were levelled at organisers and politicians after the estimated costs topped $50 billion, making them the most expensive Olympics ever held.
Officials dispute the figure, and say that many of the huge construction projects associated with Sochi will help turn the area into an international sports centre of the future.
They hope one of the main lasting legacies will be a Formula One racetrack being laid in and around the Olympic Park, which is scheduled to be ready for Russia's Grand Prix on Oct. 12.
But Sergei Kolesnikov, a Russian biophysicist who campaigns to expose what he says is major corruption in the country, said during a visit to Washington this week that Sochi may not end up as the triumph Putin hopes it will be.
"I think... the Olympics drives many Russians crazy because the standard of life is decreasing," he said.
"Everyone is going to look back from this and remember only that $52 billion was thrown away for nothing... everybody knows how much money was stolen to make the Olympics happen, so what should we be proud of?" (Additional reporting by the Reuters Winter Olympics team in Sochi and Rosa Khutor and John Shiffman in Washington, editing by Mitch Phillips.)