Hosts and defending champions Canada narrowly overcame 3-2 at the Rogers Arena to lead Group A with six points. 

Cody Glass, MacKenzie Entwistle and Noah Dobson all scored for the Canadians, while Philipp Kurashev got both goals for the Swiss team.

The victory continued the host's unbeaten run against Switzerland at under-20 level, with the Canadians having won 23 times since their first meeting in 1979. 

"They played a good game," said Glass.

"They play together, and they're fast. 

"But in the end, we came out with the win, so that's all that matters."

Russia are now second in Group A after they comfortably dispatched Denmark 4-0.

Vitali Kravtsov, Alexander Romanov, Pavel Shen and Ivan Morozov all got on the scoresheet for the Russians in their opening match of the tournament.

Sweden beat Slovakia 5-2 in at the Save-On-Foods Memorial Centre to take the lead in Group B with six points.

They also continue their unbeaten streak in round-robin games, with the 46 game record stretching back to the 2007 World Junior Championships.

"It’s only a number, but it’s fun," said Swedish captain Erik Brannstrom. 

"We’re going to do everything to keep it going."

Finland put five past Kazakhstan to record their first points of the competition. 

Tomorrow will only see two fixtures played, with the Czech Republic meeting Russia in Group A and Kazakhstan coming up against the United States in Group B.