Owen Power's hat trick helped lift Canada (1-0) over the Czechs (0-1) by a 6-3 score in Edmonton on Sunday night.
Power, from Mississauga, Ont., became the first Canadian defenceman to score three goals in a single game at the world junior men's championship.
The first overall pick in this year's NHL entry draft by the Buffalo Sabres scored a pair of power-play goals for Canada in the second period to break a 3-3 deadlock.
"I think pucks kind of just found me,'' Power said. ``Guys did a good job of getting me good pucks in good spots to shoot.''
Cole Perfetti had three assists, Mason McTavish had a goal and an assist and defencemen Donovan Sebrango and Olen Zellweger also scored for the host country at Edmonton's Rogers Place.
Canada's starting goaltender Dylan Garand, who signed an entry-level contract with the New York Rangers last week, made 14 saves for the win.