The Swedes, the youngest team in the draw, convincingly defeated David Murdoch's Britain while Norway, dressed in their garish, multi-coloured trousers pushed defending Olympic champions Canada to extra ends before falling 7-6.
Swedish skip Niklas Edin, at 24 the youngest skip in the draw, put in a nerveless performance as the 2009 European champions had Britain on the rack.
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Sweden led 2-1 going into the sixth end, where they earned a key steal.
With his last stone Murdoch could only remove one of two counters, and the lead grew to 3-1.
Edin took command in the eighth when he earned two with a delicate tap-back, replacing Britain's shot stone in the four-foot with his shooter.
Murdoch put in an inconsistent display. In the ninth, he threw a double takeout for two to pull his rink within one, but then effectively ended the game in the tenth when he overthrew.
"Well it's actually becoming pretty standard for us. It seems at every championship we play in we lose the first game," said Murdoch.
Canada, led by skip Kevin Murdoch, overcame some tense moments to wrest a 7-6 victory from the Norwegians.
Norway were 5-1 down at one stage in the fourth end, but scored three in the fifth.
Canada blanked ends six through eight, but was forced to take one in the ninth, and Norway pulled level in the tenth to send it to extra ends.
In the tenth Martin had a tight draw around a Norwegian counter, but pulled it off to earn the victory.
Norway skip Thomas Ulsrud said his team's trousers, bought from the same company which supplies American golfer John Daly, were causing a minor sensation in Vancouver.
"I think they're starting to look pretty cool. The chicks dig them but the guys, they're more (doubtful)," he said.
Germany scored a minor upset over the United States, winning 7-5 thanks to a superb display by skip Andy Kapp while Switzerland saw off Denmark 6-5.
