Ice hockey's greatest rivals Russia and Canada remain on a gold medal collision course but must first navigate tricky quarter-finals.

Canada and Russia (also as the Soviet Union) have each claimed 23 world titles and advanced to the final eight undefeated. Now they enter the knockout phase where medal dreams shatter with a first defeat.

The Canadians say they have learnt a valuable lesson from a crushing loss to Switzerland at the Turin Olympics and vow not take them lightly when they meet on Thursday.

"They (Switzerland) won 2-0 at the Olympics and we know they have a good team," Canada coach Andy Murray told reporters. "I have an awful lot of respect for them.

"I coached eight years in Switzerland I know the kind of players they have."

Russia, bidding to end a 13-year gold medal drought, will also be wary of a Czech Republic side that squeaked into the quarter-finals on the strength of the single point they earned from battling Canada to a regulation tie before losing in overtime.

The Czechs are aiming to reach the final for the third successive year.

The other quarter-final games pit defending world and Olympic champions Sweden against Slovakia on Wednesday and the United States take on Finland on Thursday.

GRITTY EFFORTS

After a slow start to the tournament, Canada have remained focused on the task of winning a medal despite the distraction of the controversy surrounding Shane Doan's selection as team captain following allegations that the Phoenix Coyotes' forward insulted the country's Francophone minority.

Doan has ignored calls from opposition parties in Canada's Parliament that he be stripped of the honor and enters the quarter-finals as the team's leading scorer.

Canada have not excelled in any one area, relying instead on the gritty blue collar efforts that have become the trademark of Canadian teams.

"We need perfection on Thursday," said Swiss coach Ralph Krueger. "Canada is an absolute dominant favorite. It's the reality we have one NHL player and they have 21.

"But that's the great thing about sports. Everyone is going to be watching because of what happened in Turin and that's going to give us courage."

Russia enter their Wednesday quarter-final packing plenty of firepower in Washington Capitals' Alexander Ovechkin, Pittsburgh Penguins' Evgeni Malkin and the tournament's leading scorer Alexei Morozov.

The Czechs have lacked their familiar efficiency but with four world titles in the last eight years know their way to the finals.

The only country to win Olympic and world championship gold in the same year, the Swedes have quietly gone about the business of defending their world crown.

Sweden enter their game against Slovakia with just one loss, falling to Russia 4-2 in their final qualifying round contest.

The U.S., chasing their first world championship title in 47 years, have brought a young, explosive team to Russia that has looked capable of ending the long drought.

The Americans, led by St. Louis Blues Lee Stempniak, have shown lots of offensive skill and will need all of it against a Finnish team that has surrendered just eight goals in five games.