Moser, a member of the Nashville Predators, ended Latvian hopes for an upset to start an event that has put the National Hockey League season on hold for two weeks.
Jonas Hiller of Anaheim made 21 saves for the Swiss in the Group C game. The 12 countries are divided into three groups with the top two from each group drawing automatic berths in the quarterfinals.
Edgars Masalskis stopped 38-of-39 shots for Latvia.
In the other Group C game on opening night, Sweden came up with two goals from Erik Karlsson, built a 4-0 lead and downed the Czech Republic 4-2. Sweden has won the Olympic gold medal in two of the last four Games.
The United States will meet Slovakia and Russia will play Slovenia in Group A on Thursday. Group B games will find Finland playing Austria and Canada facing Norway.