Kiprusoff turned aside all 27 shots he saw, improving his season's record to 28-20-5. The Calgary goalie was especially tested in the third period when he stopped 14 shots.
The Flames scored 5:39 into the final frame when Alex Tanguay forced defenseman Tyson Strachan to turn the puck over deep in the St. Louis zone and poked it to Moss, who fired the puck past Blues goalie Ben Bishop.
Calgary avoided a three-game losing streak with the win and stayed in the Western Conference playoff hunt.
Bishop took the hard-luck loss despite stopping 19-of-20 shots.