Ryan Nugent-Hopkins and Ryan Strome scored in the first period, and Canada beat the United States 2-1 to advance to the next round at the junior ice hockey world championships.
Jacob Trouba scored for the U.S. The Americans need to beat Slovakia on Monday in Group B to move on.
The 19-year-old Nugent-Hopkins was the first pick of the 2011 NHL draft by Edmonton. The center had 52 points in 62 games for the Oilers last season.
In Group A, Finland beat Switzerland 5-4 on a shootout goal by Markus Granlund, who also scored twice in regulation.
Later Sunday, Latvia plays the Czech Republic and Slovakia faces Germany.