San Francisco Frontiers - Teenage skater Valieva takes Olympic centre stage as Su upstages Gu

The 15-year-old Valieva is going for a second figure skating title at the Games but admitted that she is "tired emotionally" after her doping controversy of recent days.

The Court of Arbitration for Sport ruled on Monday that she could carry on at the Olympics, but it does not mean that the Russian has been cleared of doping and could still face punishment at a later date.

"These last few days have been very difficult for me," Valieva, who will be the favourite when the women's singles competition begins later Tuesday, told Russian television.

"I am happy but at the same time tired emotionally."

Starting to cry, she added: "These are tears of happiness, but also it seems sadness."

The CAS ruling was celebrated in Russia but provoked fury elsewhere, with the United States Anti-Doping Agency accusing the country of "hijacking" the Beijing Olympics.

It also put the spotlight once more on doping by Russian athletes, who are not allowed to take part at these Games under their flag because of a state-sponsored doping programme that reached its peak at its home 2014 Sochi Olympics.

The International Olympic Committee says there will be no medal ceremony in Beijing if Valieva comes in the top three of the singles event when it concludes on Thursday -- unprecedented in the history of the Games.

Valieva led Russia to team gold last week, before a Stockholm laboratory reported that she had failed a drugs test from December 25 for trimetazidine, which boosts endurance.

The medal ceremony for the team event will also not take place.

In ruling that Valieva should not be suspended, CAS said that there were "exceptional circumstances", including her age and the fact it had taken six weeks for her failed test to be reported.

Senior IOC member Denis Oswald told reporters in Beijing that Valieva informed her doping hearing that she tested positive because of "contamination" from her grandfather's medicine.

Russian media said Valieva allegedly drank from the same glass that her grandfather, who takes medication for a heart condition, had used.

- Whatever Gu can do -

Nine gold medals were up for grabs in the Chinese capital on Tuesday.

Corinne Suter won the women's downhill to confirm Switzerland's alpine skiing dominance.

Her victory followed Swiss gold-medal showings by Lara Gut-Behrami in the women's super-G, while Beat Feuz won the men's downhill at the start of the Games and Marco Odermatt took the men's giant slalom.

Two-time skiing gold medallist Mikaela Shiffrin, who is yet to win a medal in Beijing, came 18th.

Defending champion Sofia Goggia of Italy took silver, capping a remarkable return to form after she injured her knee in a crash last month.

There was another Swiss winner earlier in the day in the form of Mathilde Gremaud in women's freestyle slopestyle.

Gremaud triumphed ahead of Californian-born Chinese sensation Eileen Gu, the face of the Games and gold-medal winner last week. Gu, 18, had to settle for silver.

Her Chinese team-mate Su Yiming, who is 18 later this week, also now has one silver and one gold after he dominated the men's snowboard Big Air to take the title even before his third and final run.

In a touching moment, Su pointed at his parents when he was standing on the podium.

"I haven't seen my parents for the past seven months because I went to Europe for training and to many places for competitions," said Su, a film actor as a child.

"This moment is so special for me and also my family."

Austria's Anna Gasser won a dramatic snowboard women's Big Air gold to retain her title.

V.Mitchell--SFF