Defending champions Switzerland impressed throughout the round-robin stage, going unbeaten, and their quest for a third successive world title remains on track after they beat Sweden 7-5.

In a tight contest the teams were level at 3-3 after four ends, before Switzerland scored one on the fifth and forced a blank end on the sixth to give themselves a 4-3 advantage.

The teams exchanged doubles in the next two ends, with the Swedes going 5-4 in front before the Swiss retook the lead 6-5.

After a blank ninth end, Switzerland stole one shot in the final end to secure a hard-fought victory, after Swedish skip Anna Hasselborg was heavy with a draw shot.

In the second semi-final, South Korea produced an impressive comeback win over Canada, scoring on each of the last three ends on the way to a 9-6 victory.

The teams were deadlocked at 3-3 at the halfway stage of the contest, before South Korea nudged in front by scoring one on the sixth end.

Canada reclaimed the lead with the biggest scoring end of the match as they managed three points in the seventh, to go back in front 6-4.

South Korea levelled the match in end eight with a score of two, before errors from their opponents allowed them to steal a single shot on the ninth and a double on the tenth to earn a 9-6 win.

Switzerland and South Korea finished first and second in the round-robin stage to ensure direct qualification to the semi-finals.

Earlier in the day Canada and Sweden had secured last four places by winning qualification matches.

Canada edged past Denmark 9-8, withstanding a fightback from their opponents who came up just short despite scoring in the last two ends.

Sweden also booked their semi-final spot in dramatic fashion, scoring four shots on the last end to beat the United States 8-4.

Action at the CN Centre is scheduled to conclude tomorrow with Sweden facing Canada in the bronze medal match, before Switzerland and South Korea contest the gold medal match later in the day.