Mikael Granlund and Cutter Gauthier each scored in the shootout after Artturi Lehkonen tied it 1-1 for Colorado with 3:39 remaining in the third period.
Lehkonen scored on a one-timer short side past Dostal’s glove from the right circle off a crossing pass from Brock Nelson, who took the puck down to the bottom of the left circle before finding Lehkonen.
Jeffrey Viel scored, and Gauthier and Radko Gudas each had an assist for the Ducks (26-21-3). Dostal won his fourth consecutive start.
Anaheim forward Alex Killorn played his 1,000th NHL game.
Scott Wedgewood made 16 saves for the Avalanche (34-5-9), who are 3-4-1 in their past eight games.
Viel gave the Ducks a 1-0 lead at 1:27 of the second period after his wrist shot went through the legs of defenseman Sam Malinski and past the blocker of Wedgewood. Gauthier took the puck into the zone and down the right wall before feeding Viel in stride for the shot from just above the left circle.
Anaheim forward Mason McTavish was a late scratch after warmups due to an upper-body injury.
