Strachan failed to control Colaiacovo's cross-ice pass deep in his own end. When Strachan did corral the puck, his clearing attempt was knocked down by Alex Tanguay, who fed Moss. He quickly snapped his 15th goal past Ben Bishop before being wiped out by a sliding Colaiacovo.
"Tangs made a great play to get it over to me and I knew I had to get it away quickly," Moss said.
Bishop, a 6-foot-7 rookie making just his third start, said he didn't pick up the puck until it was too late.
"It happened real fast. Carlo went down to block it and he didn't really necessarily screen me, but Moss shot it right through him and I picked it up a second too late," Bishop said.
St. Louis pressed hard in the closing moments and nearly tied it with 3 minutes remaining.
Brad Boyes, traded to Buffalo after the game for a second-round pick in this year's draft, banked a shot in off Kiprusoff from the side of the Flames' net, but the goal was waved off by back referee Dan O'Rourke, who judged St. Louis forward David Backes had knocked the puck out of the air with a high stick.
A minute later, Patrik Berglund's shot beat Kiprusoff cleanly but caromed off both posts.
"These points are so big, especially for those guys who are barely in and have played a few more games than the other teams and for us who are clawing for our lives," Backes said. "We knew it was going to be like that, a playoff atmosphere, and you see a 1-0 game where it's, try to make the other team make the mistake that costs them the goal, and they were able to do that to us."
Calgary (32-23-9) finished its five-game homestand 3-1-1 and sits alone in sixth place in the Western Conference. There are four teams one point back of the Flames, and Anaheim is two points behind. Of those five teams in pursuit, three have two games in hand and the other two have one game in hand.
"This time of year, you need to be prepared to win games whatever way," Flames coach Brent Sutter said. "Games are going to be tight and you've got to win those tight games. It's playoff hockey, you're not going to get 6-5, 7-6 hockey games. You look around the league at all the games that matter in the standings and they're all one-goal and two-goal games and low scoring."
St. Louis (28-25-9) lost for the fourth time in five games and remains in 13th place in the conference, seven points out of the final playoff spot.
"If we played the way we did tonight for our first 61 games, I'd like our chances and our record better than it is right now," Backes said. "But, there are no moral victories this time of year. We need to climb the standings and make sure we're getting our two points, and the bottom line is we didn't get it done tonight."
The teams meet again Tuesday night in St. Louis. They could have a different look by then, with the NHL trade deadline set for Monday. Apart from dealing Boyes, the Blues picked up right wing Chris Stewart and defenseman Kevin Shattenkirk from Colorado in a four-player deal Feb. 18.
Stewart had racked up six goals in his first five games with the Blues but was held off the scoreboard Sunday. His best chance came late in the third, one of the Blues' 14 shots in the period, but Kiprusoff got a blocker on his close-in shot that came on St. Louis' third and final power play.
Bishop, who was coming off a 39-save shutout of Edmonton on Friday, finished with 19 stops.
Kiprusoff's best save came midway through the second when defenseman Alex Pietrangelo skated in all alone, but Kiprusoff kicked out a pad as Pietrangelo went to his backhand.
"He certainly stole one for us tonight," Moss said. "They were shooting everything and they were coming pretty hard and he shut the door and made some huge saves when we needed them."
It was the 39th career shutout for Kiprusoff, who was making his 16th straight start.
- St. Louis C Vladimir Sobotka did not return to the game after taking a Iginla slap shot off the foot in the first period.
- Tanguay played in career game No. 800.
- Calgary rookie Greg Nemisz did not play in what would have been his first NHL game. The 20-year-old was recalled Saturday from Abbotsford (AHL) given the uncertain status of RW Tim Jackman (eye) and LW Niklas Hagman (flu). However, both ended up playing.
- The Blues' lineup featured seven players who didn't play when St. Louis lost 4-1 to Calgary on Jan. 26.
- St. Louis failed to score on the power play for the first time in nine games.