Canada took the outright lead in women's Olympic curling Thursday, beating Denmark 8-5 for a fourth straight win and leaving it as the only undefeated team in the tournament.
Switzerland's unbeaten run ended with a 9-8 loss to two-time defending champion Sweden, leaving both teams with 3-1 records.
World champion Britain was under pressure after losing two of its first three games but beat China 8-7 to revive its chances of reaching the semifinals.
A day after making a mistake with her game-deciding final shot in a 9-6 loss to the Canadians, British skip Eve Muirhead was left with a routine draw into the 4-foot ring to seal victory against the Chinese.
This time, she nailed it.
"I'm really glad we came back with the strong performance there," Muirhead said, "and really glad I managed to play a great shot to finish off that game.
"We realized how important that game was ... to get that win was essential."
The Canadians have won their opening four games, defeating big rivals Sweden and Britain along the way, as they seek their country's first Olympic gold medal in the women's event since 1998.
In skip Jennifer Jones, Canada has probably the hottest women's player in Sochi and she opened up a close game against the winless Danes by picking up three points in the ninth end to give her team the 8-5 cushion.
Canada plays Switzerland in the evening session and the medal round is already in sight for the nation where curling is the No. 2 winter sport.
The Swiss had beaten the United States, Denmark and South Korea in their first three games but decided to change their lineup against Sweden, dropping Janine Greiner to alternate and calling up Alina Paetz.
The result? A first loss of the tournament as Sweden skip Margaretha Sigfridsson got a point at the final end with the hammer.
"We won all our first three games," Switzerland player Carmen Yeung said, "but we did not play well. Today we were facing Sweden and Canada so we needed to change something."
The United States (0-4) takes on Japan in the evening, and a loss would likely leave them too much to do qualify for the semifinals.