OSTRAVA, Czech Republic -- Joonas Oden scored late to give Finland a 1-0 victory over the United States on Thursday and send the defending champion into the semifinals of the world junior hockey championship.

In a rematch of last year's final, Oden broke the deadlock on a power play 4:23 into the final period, one-timing a shot from the slot past goaltender Spencer Knight at Werk Arena in Trinec.

The U.S. pulled Knight for an extra attacker and a 6-4 advantage with 1:15 left but Finland held on.

Earlier, Canada and Russia also reached the semis.

Alexis Lafreniere marked his return from injury with a goal and an assist as Canada routed Slovakia 6-1.

Lafreniere wristed a shot past Slovakia goaltender Samuel Hlavaj to increase Canada's lead to 5-0 on a power play midway through the second period at the Ostravar Arena in the eastern city of Ostrava.

The 18-year-old center, who is projected to be the No. 1 pick at the 2020 NHL draft, recovered from a left knee injury he sustained against Russia in the team's second group-stage game on Dec 28. He missed the following two games against Germany and the Czech Republic.

Captain Barrett Hayton scored two goals and added an assist for Canada.

Lafreniere assisted on Hayton's opening goal in the first period. Connor McMichael, Jacob Bernard-Docker and Liam Foudy contributed second-period goals to build a decisive lead for the Canadians.

Hayton scored his second on a power play in the final period.

Oliver Okuliar spoiled goaltender Joel Hofer's shutout bid with a late consolation goal.

Canada is the most successful team at the world juniors with 17 titles but is looking to bounce back from a disappointing sixth-place finish last year when it hosted the event.

In Trinec, Dmitri Voronkov scored two power-play goals and Russia beat Switzerland 3-1 to become the first team to reach the semifinals.

Alexander Khovanov also had a goal and an assist and goaltender Yaroslav Askarov made 14 saves as Russia outshot the Swiss 36-15 in Trinec.

Gaetan Jobin scored for Switzerland.

Russia, which also beat Switzerland in last year's bronze medal game, last won the title in 2011.

The semifinal pairings will be determined after the last quarterfinal between Sweden and host Czech Republic, according to new rules based on rankings at the event.