Casey Mittelstadt, a freshman forward for the Gophers, scored two goals as the U.S. team routed Denmark 9-0 on Tuesday night in its first game of the World Junior Championship in Buffalo, N.Y.

Kieffer Bellows, an Edina native playing in the Western Hockey League, also had two goals for the Americans. Bellows scored on a power play to make it 2-0 and then, in the second period, on a penalty shot for a 6-0 lead.

Mittelstadt, named the U.S. player of the game, had the third and fifth goals — his second goal came with 1 minute, 12 seconds left in the opening period.

Max Jones, Kailer Yamamoto, Patrick Harper, Andrew Peeke and Dylan Samberg, a Minnesota Duluth defenseman, had the other goals for the U.S. team, which had a 36-17 advantage in shots.

“When we get the puck on our sticks, we are pretty dangerous,” Mittelstadt said in an interview with the NHL Network.

“We want to keep playing our game. We have a lot of learning to do, and it’s a long tournament.”

Next, the U.S. team plays Slovakia at 7 p.m. Thursday.

Czech Republic 5, Russia 4: Filip Zadina and Filip Chytil scored second-period goals as the Czechs stunned the Russians in the tournament opener.

Russia has earned a medal in the past seven World Juniors while the Czech Republic has not reached the medal round since 2005. This was just the Czechs’ second victory in the past 12 meetings with Russia.

Martin Necas, Filip Kral and Ostap Safin also scored for the Czech Republic and Martin Kaut had three assists. Josef Korenar made 34 saves.

Zadina and Chytil scored to give the Czech Republic a 4-2 lead late in the second period. Filip Kraul scored the Czech Republic’s fifth goal 6 minutes, 16 seconds into the third period.

Artur Kayumov and Vladislav Syomin scored late in the third period for Russia.

Sweden 6, Belarus 1: Lias Andersson scored twice for the Swedes while Elias Pettersson and Erik Brannstrom each added a goal and an assist.