OSTRAVA, Czech Republic -- Russia scored three opening-period goals on the way to stunning Canada 6-0 at the world junior hockey championship on Saturday.

Canada forward Alexis Lafreniere, who is projected to be the No. 1 pick in the 2020 NHL draft, also left the ice with the help of his teammates after picking up what seemed to be an injury to his left leg in the second period.

It was the worst defeat for Canada since the tournament became official in 1977. In the 1976 edition, when it was an invitational event, the team was thrashed 17-1 by Sweden.

"They played a great game," Canada captain Barrett Hayton said. "We weren't good enough. We got behind early again tonight and it's tough to come back. We have to be better, and we will be."

Alexander Khovanov, Pavel Dorofeyev, Nikita Rtishev, Nikita Alexandrov, Yegor Sokolov and Grigori Denisenko scored as Russia recovered from a 4-3 loss to the Czech Republic hosts in the opening game on Thursday.

Khovanov, Alexandrov and Denisenko added an assist each.

Goaltender Amir Miftakhov stopped 28 shots for the shutout in the Group B game.

Khovanov set the pace, scoring 1:44 into the game with the help of a lucky bounce off goaltender Nicolas Daws. Dorofeyev and Rtishev then put the Russian team in command with two more goals in the opening period.

Canada pulled off Daws for Joel Hofer after Alexandrov made it 4-0, 2:18 into the second period.

Daws allowed four goals from 18 shots.

But Hofer couldn't stop Sokolov and Denisenko increasing the Russian lead to 6-0.

Canada, which beat the U.S. 6-4 to open the tournament, next faces Germany on Monday.

All five teams in Group B have one win and a loss after two games.

In Group A, Sweden tops the standings after beating Switzerland 5-2 with Samuel Fagemo scoring twice.

Finland got its title defense back on track by routing Slovakia 8-1 in Group A with Aku Raty netting two goals. The Finns lost 3-2 in overtime to Sweden in their previous game.

The host Czechs were upset 4-3 by Germany in Group B, with Dominik Bokk scoring twice for the Germans.