Trumbull had beaten the Warriors in the state quarterfinals last season.
Henry Lee, Alex Pagliaro and David Craven scored the goals for Wilton, which is now 3-13.
Joey Cullinan, Michael Lash, Christian Hansson, Ned Zawislak and Pagliaro had one assist apiece for Wilton.
Following a scoreless first period, Wilton got two goals in the second period to take a 2-0 lead. Each team scored once in the third period.
Wilton goalie Nick Wells finished with 30 saves.
Trumbull dropped to 4-10 with the loss.