MALMO, Sweden - Providence's Jon Gillies made 23 saves to help the United States open its world junior title defence with a 5-1 victory over the Czech Republic on Thursday.
Miami of Ohio's Riley Barber, Denver's Will Butcher, Minnesota's Hudson Fasching, Colorado College's Jaccob Slavin and Notre Dame's Vince Hinostroza scored for the United States.
In the other Group A game, Anthony Mantha scored three goals in Canada's 7-2 victory over Germany. Josh Anderson, Bo Horvat, Sam Reinhart, Nic Petan added goals for Canada.
The U.S. will play Slovakia on Saturday, Germany on Sunday, and finish group play Tuesday against Canada.
In Group B, Sweden beat Switzerland 5-3, and Russia routed Norway 11-0.