Miro Aaltonen scored twice and added an assist before leaving the game with a serious ankle injury Wednesday as Finland defeated Latvia 5-1 at the world junior hockey championship.
Rasmus Ristolainen added a goal and an assist for the Finns (1-0), while Artturi Lehkonen and Markus Granlund also scored. Joel Armia chipped in with two assists.
Joonas Korpisalo made 11 saves to get the win in Pool A.
Aaltonen had to leave the game after a third-period collision with a Latvian player.
"His tournament is over because his ankle is very bad," said Finnish coach Harri Rindell, adding the 19-year-old forward may require surgery. "He was so depressed because he really wanted to play and he is in great shape. That's hockey, unfortunately."
Nikolajs Jelisejevs had the only goal for Latvia (0-1), which got 39 saves from Elvis Merzlikins.
Latvia will take on Switzerland in that country's tournament opener Thursday, while Finland faces the Czech Republic (0-1) on Friday.