The chances were there again in this game, the opportunities created, but getting the puck over the goal-line remained an uphill battle as the team was held goalless for the third time in their last four games.
The team held a players' only meeting in the locker-room after the defeat.
David Rittich got the start, ending the night with 26 saves as his team outshot the Blues 40-31.
A goalie's best friend is the iron and that was certainly the case early in the contest.
Less than a minute-and-half after puck drop, Colton Parayko set up shop to the right of Rittich and feathered a perfect pass cross-ice to Ivan Barbashev, who got off his shot before Rittich was able to get back across the crease.
Staring at an open net, the Blues forward put it up and off the cross-bar on his team's first shot of the tilt.
Like they say, you have to be good to lucky.
Rittich showed off that good part a few minutes later.
Like, smack-your-forehead, did-you-just-see-that type of good.
Blues sniper Jaden Schwartz managed to sneak in behind the Flames defence and parked himself near the top of the blue paint. An alert Brayden Schenn quickly got him the puck, Schwartz turning and trying to put it far-side but Rittich kicking out his left pad to deny him for a 10-bell stop.
The rebound, however, went straight out and onto the stick of Tyler Bozak as he came flying into the slot, snapping a shot that Rittich gloved - able to recover from the first save in lightning-quick fashion while still down on the ice.
Zach Sanford opened the scoring at 12:07, skating the puck into Calgary's zone and dropping a pass for Robert Thomas, who spun a few circles on the left side of the ice before feeding it back to Sanford who was near the top of the faceoff circle, dropping to one knee as he one-timed it home.
Sanford nearly got his second later after a turnover gave him another great chance, this time in tight, but Rittich was there to slam shut the pads on the five-hole attempt.
A weird bounce sent Oskar Sundqvist off on a breakaway in the second period, snapping a wrister that Rittich got a piece of with his glove but it had enough left to skim over and float into the back of the cage at 6:23 to give St. Louis a two-goal cushion.
Blues defenceman Vince Dunn laid a big hit on Andrew Mangiapane later in the frame, Zac Rinaldo taking exception and grabbing him leading to a dog pile of players near the boards. Rinaldo was given a roughing penalty, sending the Blues to the powerplay.
They made good on it 24 seconds in.