Tri-City (12-6-2) won its third game in three nights — all at home — to move to the top of the U.S. Division with 26 points.
Vancouver (5-12-0) remains last in the Western Conference with 10 points.
"When you work hard, sooner or later it will go your way," Tri-City coach Jim Hiller said. "We got great contributions all weekend."
The Americans also got goals from Beau McCue and Michal Plutnar.
Tri-City rookie goalie Brenden Fiebelkorn won his first career start, finishing with 14 saves, and stopped a penalty shot by Trevor Cheek at 13:41 of the second period.
The Americans led 2-0 after the first period, then exploded for five goals in the second for a 7-0 lead. Feser competed his fifth career hat trick at 1:54 of the third period, giving Tri-City an 8-0 lead.
Cheek had the Giant’s lone goal at 4:55 of the third. Payton Lee and Tyler Fuhr combined for 29 saves in the loss.