Chris Durno and Milan Hejduk also scored for the Avalanche, who have won three of their last four games.
Durno put the Avalanche ahead 1-0 in the first period when his pass from behind the net struck Auld's stick and bounced into the net. The goal was the first of Durno's NHL career.
"It was a tough bounce to start the game and they took it to us after that," Auld said.
Colorado took a 2-0 lead with 5:56 left in the second period on Hejduk's goal.
After Ott scored at 7:44 of the third period, Stewart notched a goal on a wrist shot with 6:26 left to play and added an empty-net score in the final minute of the contest.