Olli Jokinen and David Moss each added a goal and three assists for the Flames, who used the win to jump over idle Minnesota into the eighth and final playoff spot in the Western Conference.
The Avalanche dropped their eighth straight game after receiving the emotional news earlier in the day that forward Peter Forsberg was retiring from hockey after a two-game comeback attempt.
The nine goals were the most the team has allowed since it moved to Colorado from Quebec in 1995.
Daniel Winnick got the Avs' only goal. Peter Budaj started the game, was pulled and later reinserted, turning aside 13-of-18 shots in all, and Craig Anderson stopped 11-of-15 shots for Colorado.