Backlund nearly added a second for the Flames before the period was through, but his shot off a 2-on-1 feed from Coleman struck the right post and stayed out.
Artturi Lehkonen evened the score at 1-1 at the 11:25 mark, and the two sides skated to their respective rooms even at the intermission.
Dustin Wolf was the busier of the two netminders Tuesday, and as was the case Sunday against the Mammoth, he was on his game against the Avalanche. He read a Jack Drury deflection smartly before stoning Calgary product Cale Makar on a short-handed breakaway late in period two. Then, he turned away a two-man breakaway, stopping another Calgarian - Logan O'Connor - at his left post.
But the Avalanche grabbed the lead with just under five minutes left thanks to their captain, Gabriel Landeskog, who deflected a Brett Kulak point shot home for his 14th goal of the campaign.
Nathan MacKinnon rounded out the scoring with an empty-netter in the final minute.
During the first period, the Flames honoured former Calgary center Nazem Kadri, who despite not dressing Tuesday made his first visit back to the Scotiabank Saddledome since being traded in March.