Both have now lost just once in six matches so far, with three more round-robin stages to come.

Scotland triumphed 9-2 over Sweden before winning 10-3 over South Korea in just eight ends.

The US were forced to dig deeper, beating Norway 9-6 and Russia 5-3, both matches going the full 10 ends. 

Switzerland had also been tied for the lead after a 5-3 victory over Russia this morning.

They then surprisingly lost 6-3 to Norway later.

They now lie joint third with defending champions Canada, who recovered from successive losses with two heavy wins today.

They beat South Korea 12-2 and Denmark 9-1.

The Danish hosts did, however, gain a first win of the competition today, overcoming Turkey 6-4.

The Championships were originally awarded to Erzurum in Turkey, but were reallocated to Denmark last month due to security fears.

Canada and South Korea remain in top in the women's competition after each continued their unbeaten records today.

Canada had the tougher test against third-placed US, being taken to the final stone before a mistake by American skip Cory Christensen handed the gold medal favourites a 5-3 victory.

South Korea endured a similarly close tussle before winning 7-6 over Sweden.

Russia kept their quest for a place in the playoffs alive with a 5-2 win over Scotland in a defensive game that featured four blank ends.

Hungary also remain in contention following their 8-7 win over Japan, sealed with a score of two points in the 10th end.

Switzerland beat a Turkish team that could only field three players in the final game of the session, 10-4.