"It was an important three points for us to get today against a very well-coached team," U.S. coach John Hynes (New Jersey Devils) told the USA Hockey website. "We'll take tomorrow off after playing back-to-back games and get ready for our game against Germany on Sunday."
The United States is third in Group B with nine points on three regulation wins and two regulation losses (3-0-0-2). Canada leads the group with 12 points. The top four teams in each group advance to the quarterfinals on May 19.
Larkin extended his point streak to four games with a second-period goal. He has two goals and six points in five games.
Istvan Sofron scored with 2:01 left in the third period, and Adam Vay made 32 saves for Hungary.
Hungary is eighth among eight teams in Group B with zero points.
OTHER RESULTS:
Czech Republic 3, Kazakhstan 1: Tomas Plekanec (Montreal Canadiens) scored two goals in preliminary-round play in Group A at Ice Palace in Moscow.
Czech Republic leads Group A with 14 points on four regulation wins and one overtime win (4-1-0-0). They have outscored their opponents 21-6.
Robert Kousal scored an empty-net goal, and Pavel Francouz made 19 saves for Czech Republic.
Nigel Dawes scored with 4:30 left in the third to pull Kazakhstan to within 2-1. Kazakhstan is eighth in Group A with two points.
Denmark 3, Latvia 2 (SO):Nicklas Jensen (New York Rangers) scored in the third round of a shootout to give Denmark the win in preliminary-round play of Group A at Ice Palace in Moscow.
Denmark goalie Sebastian Dahm made 30 saves, including 14 in the third period and overtime. Dahm stopped Andris Dzerins and Kaspars Daugavins in the shootout. Lars Eller (Montreal Canadiens) scored for Denmark in the first round of the shootout, and Miks Indrasis scored for Latvia in the second round.
Denmark is fifth in Group A with six points after five games. Switzerland is fourth with seven points in four games.
Germany 5, Belarus 2:Goaltender Thomas Greiss (New York Islanders) made 16 saves in his debut for Germany in a Group B preliminary-round game at Yubileiny Arena in St. Petersburg, Russia.
Brooks Macek had a goal and an assist and Marcel Noebels had two assists as Germany moved into fourth place in Group B with seven points after five games.
Patrick Reimer, Leon Draisaitl (Edmonton Oilers) and Felix Schutz scored to give Germany a 3-0 lead in the first.
Andrei Stepanov and Andrei Stas scored for Belarus, which is seventh in Group B with three points.
