Rhona Martin conceded the defence of her team's Olympic curling title was hanging by a thread after Great Britain's 10-5 defeat to Japan took semi-final qualification out of their hands.

Even victory in their final round-robin match against the United States at Pinerolo tonight may not be enough to ensure Martin's team another shot at a medal match.

The best Britain can hope for now is a Tuesday tiebreaker. But provided they beat the second-bottom USA, they will still be eliminated if both Norway and Canada each win one more match.

Martin's team never recovered from falling 6-1 behind to the improving Japanese at the fifth end and were eventually forced to admit defeat with an end to spare.

Martin said: "I would put our chances of qualifying at very low at the moment. We are relying on other people, and they are very unlikely to lose.

"We are not playing well enough at the moment, and that is the bottom line. We have still got a very tough game tomorrow, and we have got to look hard at what we are doing."

It was a different story for David Murdoch's British men's team who guaranteed an Olympic medal match despite suffering their second defeat of the round-robin phase, a 9-8 reverse to the United States.

While Murdoch's team have shown admirable consistency throughout the tour-nament, Martin's have been hit and miss, and vice-captain Jackie Lockhart paid the price by being dropped.

She was replaced by Martin's Salt Lake City gold medal-winning team-mate Debbie Knox, but the introduction of a player well-versed in rising to the big occasion failed to improve British form.

M artin said: "Jackie accepted the decision and had no problem with it. We all knew we could have to sit a game out, because we are a five-woman team."

It will have come as little consolation to a plainly anguished Martin that her team had to endure a similar situation four years ago before recovering to strike gold.

In 2002, defeat to Germany left Martin insisting "we're out, we're dead", only for an u nexpected Swiss win

followed by two British playoff successes in one day to earn them an unlikely last-four spot.

Head coach Mike Hay said: "Now we are relying on other results to get us through, and that was the same four years ago. There are a few things that could still go in our favour, but it is out of our hands."

Murdoch's team are assured of a top-four finish and a place in Wednesday's semi-finals, with the very worst scenario for them being a play-off to decide the bronze medal.

But Murdoch will know he has plenty of work to do after the manner of their defeat to the States, who roared into a 6-1 advantage after just three ends.

Despite a gritty comeback after American skip Pete Fenson's third-end doubletake out for a four-shot gain, Murdoch's men were never likely to claw the match back.

Chemmy Alcott had to wait to begin her women's super-g bid as heavy snow at the San Sicario Fraiteve course yesterday forced the postponement of the event until today.

Sarah Lindsay squeezed into the semi-finals of the women's 1,500 metres short-track speed-skating at Palavela but finished last of six in her bid to progress further.

Atlanta Thrashers left wing Ilya Kovalchuk scored four goals as Russia booked their place in the men's ice hockey quarter-finals with a 9-2 Group B victory over Latvia.

Mikael Samuelsson's third-period powerplay marker led Sweden to a 2-1 win over the United States in Group A.

The result guarantees Sweden a quarter-final berth and virtually assures the US of finishing fourth and also going through as they have a far superior goal difference to Latvia.