Canada scored a pair of third-period goals to beat Slovakia in the quarterfinals of the World Hockey Championships, while the United States blew a two-goal lead in the third and lost its quarterfinal game in a dramatic shootout to the Czech Republic. Joe Thornton scored the winning goal with 4:22 remaining in the third period, as Canada advanced to the semifinals with a 5-4 victory over Slovakia. Thornton also assisted on the tying tally by Simon Gagne, who finished with a pair of goals. Linemate Rick Nash failed to score for the first time in the tournament, but the Columbus Blue Jackets star did add three assists in the come-from-behind win. The United States, meanwhile, opened a 2-0 lead after two periods on goals by Mike Modano and Mark Parrish, but Marek Zidlicky and Jaroslav Spacek found the net in the third period for the Czech Republic, which then got outstanding play from goaltender Tomas Vokoun in the shootout. After a 10-minute overtime failed to produce a winner, Vokoun started the five-man shootout with save on Mike Knuble's attempt, deflecting the puck with his left pad before it appeared to graze off the post. Martin Rucinsky was the first shooter for the Czechs and he made a brilliant move past an attempted poke-check by goaltender Rick DiPietro and slipped a backhander into the empty side of the cage. It would be the only goal of the shootout. DiPietro, though, made an amazing 50 saves for the United States, which was outshot 52-27 before the shootout. Doug Weight was next for the Americans and hit the post. After Jan Hlavac missed for the Czechs, Vokoun came up with the best save of the shootout, stacking his pads to deny Modano. Jaromir Jagr was stopped by DiPietro and Parrish had the upper right corner picked out on the next U.S. attempt, but again Vokoun got just a piece of the shot to deflect the puck wide. Andy Roach, a defenseman who plays in Europe and beat the Czechs with a shootout goal in last year's quarterfinals, had the final chance for the Americans. He went to his backhand, trying to beat Vokoun inside the left post, but the netminder was up to the task and made the stop to send his teammates flying off the bench in celebration. "[The Americans] knocked us out at home last year," said Vokoun. "It's always sweet when you win a close game. It sometimes feels better than winning 5-1. It was a great feeling for us." Roach, meanwhile, knew he'd have to try something different to beat Vokoun. "With the ice the way it was today, the shootout percentages are definitely in favor of the goaltender," Roach remarked. "I knew the move I made last year wouldn't work this year." The Czechs will next play Sweden in the semifinals on Saturday, as the Swedes advanced with a 2-1 victory over Switzerland. Sweden spotted the Swiss a 1-0 lead just 1:20 into the game, but Niklas Kronwall answered five minutes later and Daniel Sedin scored the eventual winner 4:43 into the second period. Canada will take on Russia in the semis. The Russians needed a shootout to beat Finland after the contest ended in a 3-3 tie. The two-time defending champion Canadians trailed 4-3 after Pavol Demitra scored a shorthanded goal for Slovakia at 3:46 of the third, but the line of Nash, Thornton and Gagne came through with two goals to win it for Canada. Gagne tied it at the 8:15 mark of the third, scoring his second goal of the game off a feed from behind the net by Nash. Thornton then netted his sixth goal of the tournament with 4:22 remaining in the period, blasting a shot from the left circle into the top right corner of the net. Slovakia had one final chance, gaining a power play with 2:44 left when Canada defenseman Robyn Regehr was whistled off for interference. Goaltender Jan Lasak was pulled for an extra attacker with under a minute to play, but the Slovaks could not score the equalizer. Lasak made 28 saves for Slovakia, while Martin Brodeur stopped 21 shots for Canada. Slovakia wasted little time in reaching the scoreboard, as Marian Gaborik beat Brodeur just 45 seconds into the contest. Dany Heatley tied it for Canada on a power play at the 5:52 mark, but Slovakia went back in front just 2 1/2 minutes later on a goal by Michal Handzus. Again, the Canadians tied it with the power play when Ryan Smyth scored with 3:13 left in the opening stanza. Canada took its first lead of the game at 4:21 of the second period on Gagne's first goal of the contest, but Demitra tied it for Slovakia on a two-man advantage just under 10 minutes later. The Slovaks were awarded a penalty shot a minute after Demitra's tying goal when Ziggy Palffy was pulled down by Regehr on a breakaway. Brodeur, though, made an incredible glove save on Palffy's penalty shot to keep it tied heading to the third. In the Czech/U.S. game, DiPietro backstopped the Americans to a 2-0 lead thanks to 31 saves through two periods. Modano put the Americans ahead at 9:18 of the first period and Parrish made it 2-0 on a power play at 5:47 of the second. The Czechs finally solved DiPietro just 1:40 into the third when Zidlicky scored, then tied at the 9:50 mark of the period on Spacek's tally. Russia fell behind 2-0 just over 12 minutes into the game, then trailed 3-2 after one period. Pavel Datsyuk tied it for the Russians midway through the second period with a shorthanded goal and the goaltenders stood tall the rest of the way to force the shootout, which lived up to its name. After the first attempt for each team was missed, Alexei Yashin scored for Russia and Niklas Hagman responded for Finland. Datsyuk then scored to again put the Russians ahead, but Niko Kapanen tallied to again tie it for the Finns. Maxim Afinogenov made it 3-2 for Russia, using a forehand-to-backhand move for the goal. Olli Jokinen had a chance to even it up again for Finland, but couldn't beat Maxim Sokolov and the Russians escaped with the narrow victory.