Iginla had two goals and two assists, Huselius scored a goal and added four assists and Langkow added two goals and an assist for the Flames, who end a season-long six-game road trip Tuesday night in Columbus.
"They've got a lot of confidence," Flames coach Mike Keenan said of his top unit. "It's obvious when they're scoring goals, they've all got a lot of offensive jump, moving the puck well. Once you gain that confidence you can really perpetuate your offense and continue to get results and that's what they have been able to do. "
The Flames were a decisive 2-for-4 on the power play, while the Blues failed to execute on all three of their opportunities in the game.
"Our power play was timely and our penalty killing was solid," said Keenan, who earned his 600th career victory. "It was very good, and that was the difference in the game for us tonight."
Iginla's third period power play goal at 7:55 proved to be the difference. It was his team-leading 23rd goal of the season.
"We want to keep our streak rolling, and it was a tough game," Iginla said. "It was a game that for a bit there was going back and forth as far as momentum."
Andy McDonald scored a goal and added an assist in his St. Louis debut, but it wasn't enough as the Blues have dropped four in a row, going 0-3-1.
"There's a good group here," McDonald said. "Things didn't go well tonight, but I was really impressed."
"I thought our young guy Nystrom had a big tilt with Salvador," Iginla said. "It sure gave them a boost, too, but it really lifted us up on the bench. I thought we were a little flat and they were pulling away at that point, but we found a way to get right back in it after that."
Huselius scored his 14th of the season just 46 seconds into the second period when he banged in a rebound of his own shot past Manny Legace for a 2-1 Flames lead.
The Blues would score two goals 1:19 apart, with Brad Boyes and Lee Stempniak giving the Blues a 3-2 lead. Boyes' goal was his team-leading 19th, while Stempniak would net his sixth in 10 career games against Calgary.
Langkow converted a turnover by the Blues' Eric Brewer with 3:31 to play in the second, with Huselius collecting the assist. It was Langkow's 13th goal of the season. Brewer tried to throw the puck around the boards and out of the zone, but the puck popped off the side of the goal, where Huselius won it from Blues rookie Erik Johnson and threw a pass to the other side of the net to Langkow.
"It was not a great pass, and it was not a great battle for the puck at the side of the net either," Blues coach Andy Murray said.
Iginla put Calgary up 1-0 at 12:05 of the first period on the power play when he tapped in Langkow's pass from just inside the crease.
McDonald would tie the game at 14:28 with his fifth of the season when he converted Salvador's pass from just inside the right circle, beating Kiprusoff with a wrist shot.
The Blues had the best two scoring chances of the first period, but Stempniak's break-in backhand rung of the left post 1:36 into the game, and Kiprusoff stopped Dan Hinote at the top of the crease with 12 minutes to play.
"It's tough right now," Tkachuk said. "We're losing ground, but we competed tonight. The bottom line is getting results. We're just creeping down in the standings right now. We had chances to win the hockey game, but too many mistakes cost us."
The last time Calgary won five straight road games on the same trip was Nov. 10-19, 1988. ... After winning the first 15 times they had scored three goals or more in a game, the Blues have now dropped three in a row. ... Huselius has 10 points (four goals, six assists) in the last two games. ... McDonald was acquired in a trade with Anaheim on Friday, sending Doug Weight, minor league prospect Michal Birner and a 2008 seventh round draft pick to the Ducks. ... The Flames have scored 22 goals during their current road winning streak. ... The Blues have allowed seven power play goals during their four-game slide, after leading the league in penalty killing for much of the season.
Copyright by STATS LLC and The Associated Press
Arena: Scottrade Center Location: Saint Louis, Missouri
Referees: Wes McCauley, Kevin Pollock Linesmen: Andy McElman, Derek Nansen
Attendance: 16,733 (87.4% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
Jarome Iginla (22)
Assists: Daymond Langkow, Kristian Huselius
Andy McDonald (5)
Assists: Bryce Salvador, Paul Kariya
Kristian Huselius (14)
Assists: Craig Conroy, Jarome Iginla
Brad Boyes (19)
Assists: Paul Kariya, Andy McDonald
Lee Stempniak (6)
Assist: Jay McClement
Daymond Langkow (13)
Assist: Kristian Huselius
Jarome Iginla (23)
Assists: Kristian Huselius, Adrian Aucoin
Daymond Langkow (14)
(Empty Net) Assists: Jarome Iginla, Kristian Huselius