Noah Hanifin had a goal and two assists, and Matthew Tkachuk had a goal and assist for Calgary (18-12-6), which has lost five of six. Markstrom made 26 saves.
"Obviously we're not happy, that's not what we came here to do, we came here for the win and didn't get it," Tkachuk said. "We did some good things, but ultimately, not enough good things. It was good to get one on the power play and they got two quick ones in the second and they had all the momentum, but we got one before the third and had a great penalty kill to start the third period.
"We should have gained some momentum, I thought we did and had some chances. We had some chances when it was 2-0 and we just have to capitalize and extend our lead and not keep a team like that in it, and we did, and they found a way to get some and they came out with the win."
Tkachuk scored on a rebound at 8:29 of the first period to give the Flames a 1-0 lead. Milan Lucic scored on the power play at 19:19 to make it 2-0, tipping in a point shot from Hanifin.
"It's very disappointing, we did a lot of things right, we created a lot of chances and in the third period, we spent the majority of the time in the O-zone and only gave up six shots in the third period," Lucic said. "It's disappointing, especially with the effort that we gave and how well we played. It's one of those things, they get life on the power play and they get themselves back in it and we deserved better than the result that we got."