James van Riemsdyk and Drayson Bowman each scored a pair of goals to lead the U.S. to a 8-2 win over Germany to open the world junior hockey championship Friday.
Bowman is a forward with the Western Hockey League's Spokane Chiefs and was named player of the game for the U.S.
Van Riemsdyk, the second overall pick in the 2007 NHL entry draft by Philadelphia, is in his sophomore year at the University of New Hampshire.
Minnesota's Jordan Schroeder had a goal and three assists in the victory. Colin White of Boston University contributed a goal and an assist.
Michigan's Matt Rust and Bowman's Chiefs teammate Tyler Johnson also scored. Spokane forward Mitch Wahl had two assists.
"No matter who you are playing, you want to have a good start to the tournament and get the ball rolling," van Riemsdyk said. "We wanted to play well, we got rid of some nerves out there and we got better as the game went on.
"We just kept it simple, making chips of the boards and getting the puck in deep. We generated a lot of offence off that."
The Americans peppered the German net with 46 shots. Timo Pielmeier, who plays for the Quebec Major Junior Hockey League's Shawinigan Cataractes, gave up five goals on 27 shots in the first two periods.
Pielmeier was replaced by Philipp Grubauer of the Belleville Bulls to start the third. Grubauer allowed two goals on 19 shots.
Thomas McCollum of the Ontario Hockey League's Guelph Storm stopped 16 of 18 in net for the U.S.
Toni Ritter and Patrick Pohl scored for the Germans, who earned promotion to this tournament by winning one of two world 'B' junior championship earlier this year.
The Americans are in a pool with Canada, the Czech Republic, Kazakhstan and Germany. They face the Czechs on Sunday.
The team with the best record at the end of the preliminary round earns a bye to the semifinals. The runner-up and third-place teams will play a quarter-final.