Mattias Weinhandl put Sweden 1-0 up 3:53 into the second period with a close-range shot on a two-man powerplay.
Teammate Dick Tarnström made it 2-0 with 1:11 remaining before the second break.
At 8:48 into the third period, Petr Cajanek put the Czechs back on track scoring on a breakaway when two of his teammates were in the penalty box but Kenny Jönsson restored Sweden’s two-goal lead with 2:14 left.
The big story of the match, however, was the stellar performance in net by Sweden’s Jonas Gustavsson, who turned away 33 shots.
Nicknamed “The Monster” by the Swedish press for his role in leading his Färjestad club to gold in the Swedish ice hockey championships just a few weeks ago, Gustavsson was nevertheless humble about his contribution to Sweden’s victory over the Czechs.
“It was thanks to our sold defensive play that we only let in one goal,” he told the Aftonbladet newspaper.
Sweden is now heading toward its ninth-straight World Championship semifinal, and will face the 2008 runner-up Canada on Friday evening in Berne.