Guenther scored his second of the game with a left-circle one-timer at 7:19 of the second period after he received a cross-ice feed from Clayton Keller.
Utah took a 3-2 lead at 13:13 of the middle frame when Cameron Hebig sent a right-circle wrist shot past Justus Annunen.
Josh Doan doubled Utah’s lead at 19:09 when he took a rebound in the blue paint and scored with a backhand shot.
Utah took a 4-2 lead into the second intermission along 28-19 advantage in shots on goal.
Keller gave Utah a three-goal advantage at 6:15 of the third period with a one-timer from the bottom of the right circle off a cross-ice backhand feed from Guenther.
The Avalanche cut their deficit to two when Malinski sent Ritchie on a breakaway where he scored with a backhand shot at 13:23 of the third.
Utah extended its lead to three at 17:58 with a short-handed empty-net goal from Jack McBain.