PYEONGCHANG, Korea, Republic Of -- A fourth loss in Olympic women's curling left Rachel Homan's team with little breathing room heading into the preliminary round's finale Wednesday.

At 3-4 following a 7-5 loss to China on Tuesday, winning their remaining games against Britain and the team from Russia was a requirement for Canada to avoid elimination from medal contention.

It's a stressful position for a team that ran the table to go unbeaten and win the 2017 world championship, but not unfamiliar, according to third Emma Miskew.

"Everyone thinks it's unknown territory for us, but we've definitely grinded it out before," she said. "We control or our destiny. If we can come out tomorrow and win, then we're in a decent spot."

The top four teams in the round robin get into the semifinals.

And the Canadian women control their own destiny only insofar as winning the last two games would get them into a tiebreaker game. A better playoff fate than that required other countries to lose.

Host South Korea (6-1) was the first women's team to secure a semifinal spot. Sweden, Britain and Japan were 5-3 with China, the United States and Canada hanging on for their playoff lives at four losses.

Since curling returned to the Winter Olympics in 1998, a Canadian team has never finished out of the medals in men's or women's curling.

Canada's Kevin Koe was in a less-precarious position in the men's tournament at 5-3, with one game to play against Denmark.

The Albertans doubled Japan 8-4 to stand tied for second with Britain (5-3) and Switzerland (5-4) behind the semifinal-bound Swedes at (7-1). Koe's win stopped a three-game losing skid.

"We had to win," lead Ben Hebert said. "We played (with) maybe a little more intensity, a little more urgency, because our backs were against the wall."

The Canadian women winning out Wednesday would pull the Brits down to four losses to force a tiebreaker.

"We were hoping to win our last three. We came up a little bit short," Homan said. "We know how to play to win our next two."

In the event three or more teams tie for fourth, their record against each other determines ranking. If still tied, the average distance of pre-game draws to the button that determine hammer is the next step.

The Canadian women were in good shape in that scenario as they ranked second after seven games behind the Swiss rink already eliminated from playoff contention.

After opening with three losses, Ottawa's Homan, Miskew and front end Joanne Courtney and Lisa Weagle seemed to get back on form with a trio of wins.

But China's Bingyu Wang, the 2010 bronze medallist, had a better hit game going than Homan at 82 per cent accuracy to 69. Miskew was outdrawn by counterpart Yhan Zou 95 per cent to 71.

Homan set up for a steal of two in the eighth end for a 6-5 lead, but her final draw hung outside of cover just far enough for Wang to rub off of to the button for a point and a two-point lead.

"I think we're still really playing a strong game," Homan said. "We missed a few lines and a few spots on the ice, but we'll come back tomorrow strong."

But smiles the Canadians had recovered winning three in a row disappeared again Tuesday. Her arms folded in front of her in post-game interviews, Miskew was expressionless answering questions from the media.

"They'll be fine. They're a tough bunch of girls. They're phenomenal shotmakers," their coach Renee Sonnenberg said. "They'll just keep setting it up and plugging away.

"The expectation is there simply because they're the best team in the world. They have high expectations of themselves."