CALGARY, Alberta -- The Flames seem to be more comfortable when they're against the ropes.
Colborne took the first attempt in the shootout and beat Jaroslav Halak on a deke for his third goal on four attempts this season in the tiebreaker.
"We've been doing it all year," Colborne said. "It seems like when we have a lead going into the third period, we're more nervous than we are when we come in and we're down."
Flames captain Mark Giordano forced the shootout, tying the game with 5 seconds left in the third period.
Patrick Berglund's holding penalty gave Calgary a power play for the final 1:37 of the third. Flames coach Bob Hartley added more pop to his offense by pulling Berra for a 6-on-4 skating edge.
Jiri Hudler's long diagonal pass was hammered in from the faceoff dot by Giordano, who one-timed a blistering slap shot past Halak to send the sellout crowd into a frenzy.
"I was just hoping he saw me because I saw the lane open right up," Giordano said. "When I saw it coming over and he laid it nice and flat for me. I just obviously tried to get a shot on net and it was a really good feeling to see that one go in for sure."
Hartley likes his team's determination when it's behind.
"We know the trademark of our team. Credit goes to our players. They never quit," Hartley said. "We don't want to fall behind but we always feel as a coaching staff that we keep supporting those guys and they always come up with a big goal, a big effort."
The Flames lead the league in one-goal games, the latest being a 4-3 loss to Pittsburgh on Saturday in which a third-period comeback came up short.
Hudler and Mike Cammalleri also scored for Calgary (14-17-6), which kicked off a five-game homestand. The Flames snapped a three-game losing streak.
"It's uncharacteristic but a learning lesson for us," Blues captain David Backes said. "We played a team tonight that played their butts off and was on an uphill trajectory all game. They got better as the game went on and we plateaued and took our foot off the gas a little bit."
The Blues looked like they had the game well under control when goals 44 seconds apart in the second period from Schwartz and Paajarvi broke open a 1-1 tie and sent St. Louis to the intermission up by two.
The Flames cut the deficit to 3-2 at 11:05 of the third when Paul Byron set up Cammalleri from behind the net for his team-leading 12th goal.
"Teams in the west will take it to you if you let your foot off the gas and this team is no different. A little credit to them, but we're going to look inside our room and make sure we're better next time we come out," Backes said.
Blues coach Ken Hitchcock spoke only briefly and echoed what his captain said.
"We lost composure with the puck. We made some puck errors. We got caught not clearing pucks at the end. We had full control of the hockey game," he said. "We were just winding the game down and made some puck errors and the next thing you know it was in our net."
Berra made 32 saves to improve to 5-8-2. Halak stopped 26 stops and fell to 17-6-3.
Flames center Matt Stajan left the game late in overtime after a knee-on-knee collision with Backes, who was penalized for kneeing on the play. There was no update after the game on his condition. ... Calgary announced that Curtis Glencross (high ankle sprain), who earlier in the year missed 15 games with a knee injury, will miss eight weeks while D Kris Russell (sprained knee) will miss the next four to six weeks. Also out is C Blair Jones (knee, indefinite). That left D Derek Smith as the lone healthy scratch... Taking Russell's spot on the Calgary blue-line was Chris Breen.... With Alex Steen (upper body) out for the Blues, 20-year-old Dmitrij Jaskin, recalled from Chicago (AHL), made his season debut and played alongside Oshie and Backes.