* South Koreans complain of figure skating bias
* Online petition demands inquiry into Russian gold
* German athlete returns abnormal doping result
* U.S., Canadian men meet in big ice hockey clash
By Mike Collett-White
SOCHI, Russia, Feb 21 (Reuters) - The scent of scandal lingered over the Sochi Olympics on Friday after contentious judging favoured an unfancied Russian over South Korea's Kim Yuna in the women's figure skating contest, and a test produced the first suspect blood sample of the Games.
As Russia's first Winter Olympics headed into the final weekend, the host nation rejoiced after snatching the coveted figure skating title for the first time late on Thursday.
Adelina Sotnikova, who few had expected to be among the medals before the competition began, eclipsed overwhelming favourite Kim despite the defending champion producing a stirring performance that many viewers had deemed to be enough.
The controversy rumbled on into Friday, when South Koreans expressed shock and anger at a decision they said had been engineered to favour the Russians.
More than 800,000 people signed an online petition demanding an inquiry into Kim's loss, which many in the country of 50 million people stayed up into the early hours to watch. "Queen Yuna" is South Korea's most loved and best-known athlete.
It was not only South Koreans who doubted the outcome.
"I am stunned by this result, I don't understand the scoring," Katarina Witt, the 1984 and 1988 champion, was heard commentating on German TV from her booth at the venue.
Russian television and radio stations lionised their 17-year-old champion on Friday, although the Sovietsky Sport newspaper referred to the scandal with the headline: "American media cast doubt over Adelina Sotnikova's victory".
Its columnist gave his own analysis as to why the result should not be called into question.
In another controversy, the German Olympic Committee announced that an unnamed athlete had returned an abnormal doping sample at the Sochi Games and a second sample would be tested later on Friday to determine the presence of banned substances.
So far no athlete has tested positive for banned drugs at Russia's first Winter Olympics, with the IOC eager to stop cheats from getting to the Games with increased testing in the months leading up to the event.
PAIN OF DEFEAT
The judging controversy and doping test were a distraction from Friday's action, when seven more medals will be decided.
With 81 out of 98 events completed, Norway leads the medals table with 10 golds, ahead of the United States and Germany on eight and Russia and Canada on seven.
The women's Alpine skiers bid farewell to the Games with the slalom in the Caucasus Mountains above Sochi, and the women also compete in the freestyle skiing skicross event.
Notable by her absence from the slalom will be Ukrainian skier Bogdana Matsotska, who withdrew from the Olympics on Thursday in protest over her government's handling of deadly anti-government demonstrations in Kiev.
At least 75 people have been killed in clashes between security forces and protesters opposed to President Viktor Yanukovich, who enjoys Russia's backing.
Russian President Vladimir Putin will be desperate for the crisis in neighbouring Ukraine not to overshadow Sochi, which he has used to project his country as a modern, tolerant state that does not deserve the Western criticism it receives.
But Russian protest group Pussy Riot, who released a music video in Sochi this week attacking the Games and Putin's human rights record, have drawn international attention to what critics say is his refusal to brook opposition.
ICE HOCKEY SUPERPOWERS CLASH
The women's biathlon relay may be postponed as the Laura venue was again wrapped in fog. The men's mass start was delayed twice and eventually held on Tuesday instead of Sunday.
Arguably the highlight of the day, though, will be the men's ice hockey semi-final between two of the sport's superpowers the United States and Canada at the futuristic Bolshoy Ice Dome.
The teams met in the last final in Vancouver in 2010, and the Americans will have revenge on their minds.
The other semi-final is also a gold medal rematch with Finland and Sweden clashing just as they did in the 2006 Turin final, which was won by the Swedes.
In the women's ice hockey final late on Thursday, Canada snatched victory from the jaws of defeat in a nailbiter that went into overtime, leaving the U.S. team devastated.
Canada face Britain in the men's curling final, seeking to emulate their women's team who beat Sweden to win gold on Thursday.
There are three more golds to be won in the unpredictable sport of short track speed skating where the favourites can often get bumped out of contention.
South Korean-born Viktor Ahn, now competing for Russia, seeks to add to his haul of four Olympic gold medals in the 500 metres and 5,000m men's relay, while Elise Christie hunts Britain's first Olympic short track gold in the women's 1,000m. (Reporting by the Reuters Olympics team in Sochi and Rosa Khutor; Editing by Peter Rutherford)