BUFFALO, N.Y. -- The United States used another late goal to continue its gold-medal defense at the world junior hockey championship.
Kieffer Bellows scored his second goal with 7:29 left in the third period to lead the U.S. in a 4-2 quarterfinal victory over Russia on Tuesday night.
Kailer Yamamoto also had a goal, Joey Anderson added an empty-netter and Joseph Woll made 27 saves for the Americans, who will play Sweden in the semifinals on Thursday.
Sweden held on for a 3-2 quarterfinal win over Slovakia earlier in the day to remain unbeaten in the tournament.
A preliminary-round loss to Slovakia put the U.S. on the tougher side of the bracket. The Americans responded to that loss with three straight wins over Canada, Finland and Russia, using third-period goals to pull out each of the victories.
"I think we're starting to play our best hockey," U.S. coach Bob Motzko said. "This tournament always has booby traps. We hit ours right away. We got through it."
Canada will play the Czech Republic in the other semifinal.
Bellows, the son of former NHL All-Star Brian Bellows and a first-round draft pick of the New York Islanders in 2016, skated into a slap shot for the winning goal. Dylan Samberg's indirect pass off the end boards bounced back to meet Bellows at the left faceoff circle.
"It was just simple hockey," said Bellows, who leads the tournament with six goals. "He put the puck deep and I knew the boards are lively back there, so I thought I could just forecheck and put the puck on net. Lucky enough it went in."
The U.S. took a 1-0 lead on Bellows' power-play goal 2:18 into the game. Bellows celebrated the goal in front of a fan in the stands wearing his father's old Minnesota North Stars jersey.
"I noticed after I saw it on the replay," Bellows said. "That's a pretty funny coincidence."
Marsel Sholokhov tied it for Russia before Yamamoto put back the rebound of his own shot to make it 2-1 late in the first period.
Andrei Altybarmakyan had the tying goal for Russia early in the third period. Vladislav Sukhachyov made 39 saves.
"We keep our game simple like we did today and good things will come," Bellows said.
Earlier on Tuesday, Isac Lundestrom scored two goals in Sweden's victory. Fabian Zetterlund scored the other goal, making it 2-0 early in the second period. Martin Bodak had both goals for Slovakia. Roman Durny made 36 saves.
The U.S. defeated Sweden 3-1 in an exhibition game before the tournament but is expecting a tougher game in the semifinals.
"We like the challenge," said Brady Tkuchuk, who scored the shootout winner and the tying goal in regulation against Canada. "It's a tough road, but we believe we can come out on top."
In the other quarterfinal games, Drake Batherson scored twice as Canada earned an 8-2 quarterfinal win over Switzerland, and Kristian Reichel and Martin Necas scored shootout goals for the Czech Republic in a 4-3 defeat of Finland.
Brett Howden added a goal and two assists for Canada, which won Group A with three wins and a shootout loss. Cale Makar, Jordan Kyrou, Conor Timmins, Dillon Dube and Maxime Comtois also scored.
Canadian goalie Carter Hart stopped 12 shots for the win.
Filip Zadina scored twice in regulation for the Czech Republic, including the tying goal with 2:26 remaining in the third period. Reichel scored the other goal. Josef Korenar made 51 saves.
Aapeli Rasanen, Olli Juolevi and Kristian Vesalainen had goals for Finland. Vesalainen also had the only Finnish goal in the shootout. Ukko-Pekka Luukkonen made 26 saves.
The Canadians beat the Czech Republic 9-0 on Dec. 20 in a pre-tournament exhibition game in London, Ontario. However, the Czechs didn't put out their full roster and had just arrived in North America.
"We played them there but haven't seen them since and they've added some really good players," said Dube, the Canadian captain. "It's going to be a really fast game and we're looking forward to the challenge.
"It's going to be a hard game."
In the opener of a three-game relegation series, Andreas Grundtvig scored with 15 seconds left in the third period to lead Denmark to a 5-4 comeback victory over Belarus.