With captain Jarome Iginla out of the lineup for the first time in nearly six years, the Flames (13-15-4) won their eighth straight game on home ice at the Scotiabank Saddledome.
The subject of trade speculation all season long, Iginla was announced as a healthy scratch just two hours before the start of the game. The last time Iginla missed a game was back on April 8, 2007 in Colorado against the Avs, a span of 441 consecutive games.
Joey MacDonald made 27 saves in the Calgary net to pick up the win. MacDonald started in place of Miikka Kiprusoff, who had played the past four games for the Flames, including the night before in Calgary's 2-0 road loss to the Chicago Blackhawks.
Avs goalie Semyon Varlamov meanwhile stopped 23-of-27 shots.
The Flames outshot the Avs 14-2 in the first period and took a 2-0 lead by virtue of a power-play goal by Hudler and an even-strength marker by Begin, his first goal in 17 games.
McGinn scored for Colorado at 4:29 of the second before Cammalleri answered back for Calgary just 12 seconds later to put the Flames up 3-1.
Shortly after MacDonald made a nice glove save to deny a great scoring chance by Steve Duchene, the backup Calgary netminder let in a weak goal when a pass by Landeskog bounced off the net, then off his skate and in.
Before the end of the second, Cammalleri one-timed a pass from Dennis Wideman past Varlamov to put the Flames up 4-2.
The Avs poured on the pressure in the third, in which they outshot the Flames 16-2, and were rewarded for their persistence when O'Reilly scored during a two-man advantage at 12:34 of the final frame.
In the late stages of the game, Colorado coach Joe Sacco pulled Varlamov from the net in favour of an extra attacker. With 25.2 seconds left on the clock MacDonald made another nice glove save to stop a shot off the stick of Duchene and preserve the one-goal victory.
Notes: Cammalleri ended a nine-goal goalless drought. He had also gone four straight games without recording a point. … While the Flames have won eight straight games at home, they've lost 10 in a row on the road, going 0-9-1 in that span. … Paranteau drew an assist on McGinn's goal to give him two goals and two assists in his past three games. For McGinn, it was his second goal in as many games.