MALMO, Sweden (AP) -- Jack Eichel, Ryan Hartman and Boston University defenseman Matt Grzelyck each had a goal and an assist, leading the defending champion United States to a 6-3 victory over Slovakia on Saturday in the world junior hockey tournament.
In the other Group A game, the Czech Republic stunned Canada, 5-4 in a shootout. Dominik Simon scored the deciding goal in the tiebreaker.
The United States scored its first three goals on power plays.
''Overall, I love to see the power-play goals we were able to get tonight,'' said U.S. coach Don Lucia of the University of Minnesota. ''The negative is we gave up the two. We just have to clean up some of the mistakes we made out there. I was happy how we played in the third period as far as 5-on-5 play to score those separation goals and put it away.''
Miami of Ohio's Riley Barber, Boston University's Dan O'Regan and New Jersey Devils prospect Stefan Matteau also scored for the Americans (2-0-0). Matteau, the son of former NHL player Stephane Matteau, plays for the Devils' Albany affiliate in the American Hockey League.
''We don't have that one player who's going to go out and score four goals,'' said Hartman, the West Dundee, Ill., forward who plays for the Plymouth Whalers in Ontario Hockey League. ''We have a well-rounded team and everyone is contributing.''
The Americans opened the tournament with a 5-1 victory over the Czech Republic on Thursday. The U.S. will play Germany (0-2-0) on Sunday, and finish group play Tuesday against Canada (1-0-1).
The United States took a 2-0 lead in the first period. Eichel, a 17-year-old forward from Chelmsford, Mass., scored with 3:07 left and O'Regan followed with a second to go.
Hartman, a first-round pick by Chicago, put the U.S. up 3-0 4:22 into the second period. But Slovakia (1-0-1) came back with a pair of goals to pull within one after two periods.
Providence's Jon Gillies stopped 27 shots for the United States.
Montreal draft pick Martin Reway scored twice for Slovakia.
''It's hard to win a game when they score almost every time they get a power play,'' Reway said.
In Group B, Sweden and Russia each improved to 2-0-0. Sweden beat Finland 4-2, and Russia routed Switzerland 7-1.
Alexander Wennberg had two goals and an assist for Sweden, and Alexander Barabanov and Damir Zhafyarov each had a goal and an assist for Russia.
Finland dropped to 1-1-0, and Switzerland to 0-2-0.