Olli Jokinen also scored, and the Flames moved to within one point of the eighth-place Chicago Blackhawks, which lost 2-0 to Tampa Bay on Sunday. The Blackhawks have played two fewer games than the Flames.
Peter Budaj made 34 saves, and Milan Hedjuk scored for Colorado, which has won only four times in 29 games.
The game was scoreless after one period, but Calgary grabbed the lead 10:23 into the second on jokinen's 17th goal. After killing off two power plays, the Flames dumped the puck deep into the Avalanche end. A clearing attempt by Colorado bounced in front of the net to Jokinen, who chipped the puck past Budaj.
Colorado kept the pressure on Calgary but Kiprusoff came up with big saves. His best stop came 90 seconds after Jokinen's goal when he made a sprawling pad save on David Jones and then smothered the rebound.
Tanguay made it 2-0 with his 21st of the season with 11:47 left in the game.
The Avalanche finally got on the board when Hedjuk buried a rebound with five minutes left for his 21st goal.
Colorado pulled Budaj for an extra attacker with 1:14 left but couldn't score the tying goal.
Both teams had great chances in the first period. Colorado's Ryan O'Reilly missed an open net when Flames defenseman Robyn Regehr deflected his shot. Jay McClement hit a post, and Jones was stopped by Kiprusoff when he came in alone.
NOTES: The Avalanche weren't called for a penalty until 14:51 of the second period. ... Calgary is 24-1-3 when leading after two periods. ... Entering Sunday's game Colorado had lost 425 man games to injury, the most in the organization's history and second in the NHL.