HALIFAX, Nova Scotia -- Jaroslav Chmelar and Matous Mensik scored 33 seconds apart during a five-minute power play as the Czech Republic stunned Canada 5-2 in the opener for both countries at the world junior hockey championship on Monday.

Stanislav Svozil and David Spacek had a goal and an assist each, and David Moravec provided the rest of the offense for the underdog Czechs.

Goaltender Tomas Suchanek was stellar in making 36 saves and an assist behind a structured, determined group.

Shane Wright, with a goal and an assist, and Connor Bedard scored for Canada. Benjamin Gaudreau allowed five goals on 17 shots before being replaced by Thomas Milic in the second period. Milic finished with 10 saves for the suddenly wobbly tournament favorites.

SWITZERLAND 3, FINLAND 2, OT

Attilio Biasca scored 41 seconds into overtime as Switzerland opened the tournament with a 3-2 win over Finland in Moncton, New Brunswick.

Lorenzo Canonica and Jeremy Jabola also scored for Switzerland. Jonas Taibel had two assists, while Kevin Pasche stopped 14 shots.

Konsta Kapanen and Kalle Vaisanen scored for Finland. Aku Koskenvuo made 24 saves.

Finland was the runner-up at the last world juniors, falling to Canada 3-2 in overtime in August.

SWEDEN 11, AUSTRIA 0

Filip Bystedt and Isak Rosen each had two goals and an assist as Sweden got off to a blazing start with an 11-0 drubbing of Austria in Halifax.

Carl Lindbom had 13 saves while also dishing out an assist for Sweden.

Thomas Pfarrmaier stopped 23 of 29 shots in 30:28 of action before being pulled for Benedikt Oschgan, who allowed five goals on 22 shots for Austria.

UNITED STATES 5, LATVIA 2

Luke Hughes, Red Savage, Chaz Lucius, Sean Behrens and Jimmy Snuggerud scored for the powerful United States in its opener in Moncton.

Anri Ravinskis and Niks Fenenko scored for Latvia.

The teams were scoreless after the first period and tied 2-2 heading into the final frame. The U.S. outshot Latvia 46-17.