“It's a damn shame,” said captain Pär Mårts to the TT news agency after the match.
The Swedes were defeated 3-1 by the Czech team, scoring their only goal in the 19th minute of the final period when Linköping's Carl Söderberg managed to get one past Czech goalkeeper Alexander Salak.
“It's the goal difference of course that made us lose. Salak is good, but you can get goals against him. Above all, we had a lot of opportunities in the first period and should have taken the lead,” Söderberg said.
The game remained tied at zero for the first two periods, but the Czechs returnd to the ice in strong form for the final term.
Just 37 seconds in, Petr Nedved scored, followed by one from Michal Vondrka. A third and final goal by Jiri Tlusty made it 3-0 with just over seven minutes remaining in the game.
Sweden's next game is against Russia on Friday.
In May, the Czechs handed the Swedes a loss at the Globe Arena in Stockholm to knock them out of the world championships.
The Karjala Cup is an annual competition held in Finland and founded in 1996. Sweden has only finished first once, in 1997, but has taken the silver medal five times.