Devon Toews had two assists for the Avalanche (47-14-6), who are 6-1-1 in their past eight games and lead the Flames by 12 points for first in the Western Conference.
"Great win. Gutsy win by our group," Colorado coach Jared Bednar said. "I thought our team was highly committed on the defensive side of things. Power play steps up at the end gets us a big win."
The Avalanche are the first team to get 100 points this season and the ninth in the past 45 years to reach the mark in 67 games or fewer.
"I'm proud of our group to this point of the season," Bednar said. "I think a heightened since of urgency, commitment, purpose, buy-in from our group. I think it says everything. We're there for a reason and we've got to give the guys all the credit."
Tyler Toffoli scored, and Jacob Markstrom made 28 saves for the Flames (40-18-8), who lead the Los Angeles Kings by seven points for first in the Pacific Division.
"Five-on-five we were good," Calgary coach Darryl Sutter said. "I think we could have got around the net a little bit more and maybe get a tip or something like that. When you're playing against a defense like that, you've got to have a little bit of courage too."