After two good wins previously, Rhona Martin's women curlers were simply overwhelmed by an undefeated Canadian team, going down by 4-9 in just eight ends.
Although Kelley Law's Canadian women came onto the ice sporting Valentine's Day hearts, they showed no charity at all to their opponents in their fourth round-robin game.
The British were in trouble from the first end, when Martin failed to clear an attempted take-out to leave Law with a simple hit and stay for two shots.
The second end was worse as Martin's last stone hit and rolled out instead of staying in the house to gift Canada a steal of two.
"Hopefully, that's our one bad game out of the way"
The British team finally put a score on the board in the third end when Martin produced a clever tap-up on one of her own stones to score a single.
But the British girls got themselves into trouble again in the fourth end when third player Debbie Knox had a complete miss on an attempted take-out, with the result being another hit for two shots by Canada.
The British girls were under real pressure again in the fifth, but a hit and stay by Martin gave her two shots and reduced the deficit to 3-6.
Canada increased their lead with a single in the sixth end, thanks to a gentle nudge-up with their last stone.
Britain took another single in the seventh to claw away at the Canadian lead.
However, Law kept the pressure up throughout the eighth end, piling in stone after stone.
When she made her final draw for two shots and a 9-4 lead, Martin's team agreed that they had had enough and conceded what had turned into a hopeless cause.
Afterwards, a downbeat Martin said: "We just got off to a bad start. Against a team like that you just can't go several down because they just don't miss."
"Hopefully that's our one bad game out of the way and we'll come back tomorrow playing a lot better."
Martin also acknowledged that her next game - against Switzerland who sit above them in the rankings - was going to be crucial.
Worryingly for Britain's semi-final prospects, Sweden's Elisabet Gustafsen brought her team back into contention with a 10-3 win over Norway.