EDMONTON, Alberta -- Petr Hauser and Matyas Sapovaliv scored in a 3:11 span of the second period, and the Czech Republic upset the United States 4-2 in the world junior hockey quarterfinals Wednesday night.
The defending champion United States dropped out after going 4-0 and never trailing in round-robin play.
"These games are tough, and we struggled to get into our game today," U.S. coach Nate Leaman said. "Our first 10 minutes were good, but we struggled to manage the puck. We played a good Czechia team, they played hard and blocked a lot of shots, and you have to tip your hat to them."
Tomas Suchanek made 28 saves to help the Czech Republic set up a semifinal against Canada on Saturday night. Earlier, Canada beat Switzerland 6-3, Sweden held off Latvia 2-1 and Finland beat Germany 5-2.
Hauser gave the Czech Republic the lead at 7:34 of the second with a wrist shot to the top corner, and Sapovaliv followed at 10:45 off a rebound.
With the U.S. on a five-minute power play for Stanislav Svozil's kneeing major, Carter Mazur pulled the Americans within a goal with 8:29 left. Jiri Kulich put it away with an empty-netter with 1:32 to go.
Logan Cooley opened the scoring for the Americans with 7:57 left in first. Jan Mysak tied it with 2:05 left in the period.
Kaidan Mbereko made 20 saves for the United States.
Canada won after sweeping its preliminary group, with Logan Stankoven scoring twice and adding an assist. Tyson Foerster had a goal and two assists, Jack Thompson, Nathan Gaucher and Will Cuylle also scored, and Dylan Garand made 23 saves.
Attilio Biasca scored twice and Simon Knak added a goal for Switzerland.
Emil Andrae broke a tie for Sweden midway through the third.
Isak Rosen opened the scoring for Sweden on a power play in the first period. Gustavs Ozolins tied it late in second. Jesper Wallstedt made 12 saves for Sweden.
Roby Jarventie had two goals and two assists for Finland. Kasper Simontaival and Joel Maatta each had a goal and an assist, with Finland scoring four times on the power play.
Roni Hirvonen also scored and Leevi Merilainen made 19 saves. Bennet Rossmy had two power-play goals for Germany.