Britain's women curlers lost 8-6 to world champions Sweden in their first defeat of the Games so far.
Skipper Martin came back strongly after the break
A nervous start by skipper Rhona Martin enabled Sweden to move into a 5-0 lead after just three ends.
Martin's team fought back to get within one point at 7-6, before the Swedes delivered a final hammer blow.
Britain are still in with a great chance of qualifying from the round-robin competition, following victories over Denmark and Switzerland.
Martin, who skippered Britain to gold four years ago, said mistakes at the second and third ends had cost her side the match.
"You can't go 5-0 down to the European and world champions," she said.
"It was not the best start to the game, but that happened to us at the Europeans and we completely flattened - so at least we fought back to the last stone."
Martin said she would lose little sleep over the defeat and was looking to Thursday's match against Russia.
She said there was still everything to play for in the women's round-robin - as all 10 teams in the competition had now lost at least one match.
"Everybody is going to beat everybody else," Martin added. "So it is about who has got the true grit and determination to get through the Games."