Jack Campbell made 22 saves and the United States remained unbeaten at the world junior hockey championship with a 3-0 victory over Switzerland on Sunday.
Chris Kreider, Matt Donovan and A.J. Jenks scored for the Americans (2-0), who opened the tournament with a 7-3 victory over Slovakia on Saturday night.
Benjamin Conz made 46 saves for Switzerland (0-1).
"He played great. I was getting a little nervous there," Campbell said. "It was one of those games where the other goalie is standing on his head while I didn't get too many shots. ... We were lucky to bury a few on him in the end."
With a partisan crowd behind them, the Swiss were the stronger team in the opening period, generating more scoring chances. Sven Ryser had a chance to put Switzerland ahead, but Campbell stopped him on a partial breakaway with 6 minutes remaining.
"Obviously it's very disappointing. We were really close," Swiss captain Luca Sbisa said. "I think we showed a lot of positives tonight. If we had put one or two in it would have been a different game."
Kreider, a Boston College product and New York Rangers draft pick, was the only player to beat Conz in the first 40 minutes. He deflected in Cam Fowler's point shot on a power play at 5:51 of the second period. Conz appeared to be screened on the shot.
Conz was sensational from that point on _ the Americans fired 38 shots on goal over the final two periods. But the Swiss couldn't convert their chances, and Donovan made it 2-0 with 7 minutes left. Jenks put the game out of reach four minutes later.
The United States will resume Group A play on Tuesday against Latvia.
Switzerland will face five-time defending champion Canada on Monday. Canada beat Latvia 16-0 on Saturday.
In the second Group A games in Saskatoon, Slovakia beat Latvia 8-3 to improve to 1-1. Richard Panik had two goals and two assists for Slovakia, and Tomas Tatar had two goals and an assist.
In Group B in Regina, Oliver Ekman Larsson and Anton Rodin each had two goals and an assist to help Sweden beat Austria 7-3.
Jacob Josefson, Mattias Ekholm and Andre Petersson also scored for Sweden (2-0), and Islanders prospect Anders Nilsson made 24 saves.
Alexander Pallestrang, Dominique Heinrich and Konstantin Komarek scored for Austria (0-2), and Marco Wieser made 47 saves.
In the late game, Finland overcame a three-goal deficit to beat the Czech Republic 4-3. Sami Vatanen scored twice, and Teemu Hartikainen and Joonas Rask added goals for Finland (1-0). The Czechs (0-2) were coming off a 10-1 loss to Sweden on Saturday.