Langkow scored twice and Iginla added a goal and two assists in the Calgary Flames' 4-1 victory over the Thrashers on Tuesday night.
Alex Tanguay also scored for Calgary, which moved ahead of Vancouver and Minnesota into first place in the Northwest Division.
Iginla and Langkow had combined for just three assists during the Flames' season-worst, four-game losing streak. Calgary converted each of its first three man-advantages against the NHL's worst penalty killers to jump in front 3-0 in the first period.
Atlanta has surrendered 11 power-play goals in five games.
"Special teams can win you games and tonight was a prime example," said Langkow, who has 24 goals, three shy of his career high. "We come out and get three power-play goals right off the bat and we rolled from there."
Calgary's slide included a 7-4 drubbing against Detroit on Sunday at the end of a disappointing three-game road trip.
"It was a real tough road trip for us, especially our last game where we didn't show up -- period," Iginla said. "As a group of forwards, when we went on the road, we weren't skating enough. Tonight, we were ready."
Denis Hamel, claimed off waivers from Ottawa on Saturday, scored for Atlanta.
The Thrashers have just one win in seven (1-5-1), and have seen their Southeast Division lead over Tampa Bay fall to just three points.
"We've been just holding on here for the last 15-20 games and we really haven't stepped up and done anything ourselves so maybe this is a wake-up call for us," defenseman Greg de Vries said. "We can see (Tampa Bay) right in our rearview mirror and they have two games on hand on us, too. If they win those games, they're ahead of us."
Iginla one-timed in a centering pass from Craig Conroy at 6:19. Langkow made it three goals on four shots at 13:59 when he converted a pass from Kristian Huselius.
"Our penalty killing, there's just no confidence right now," Thrashers coach Bob Hartley said. "We can generate so much good momentum off of our penalty killing, but right now it's hurting us big time."
The Flames are 9-0-1 in their last 10 home games and lead the NHL in wins on home ice (23-5-1).
Atlanta cut its deficit to 3-1 midway through the second period off a turnover by Flames defenseman Mark Giordano.
Giordano's clearing attempt around the side boards was intercepted by de Vries, who whipped a shot on goal. Miikka Kiprusoff made the save but the rebound kicked straight out to Hamel, who scored his fifth of the season.
It took only 16 seconds for Calgary to respond. Iginla intercepted a pass and slid the puck ahead to a breaking Tanguay. He fired a quick shot from the wing and beat Lehtonen.
Kiprusoff bounced back with a better effort after getting pulled 13 minutes into Sunday's loss in Detroit when he allowed three goals on 14 shots. He wasn't overly busy against Atlanta and made 21 saves.
His best stop came in the second when Marian Hossa burst in on a short-handed breakaway but was thwarted.
Lehtonen recovered nicely from his rocky start to finish with 23 saves.
The Flames will play Colorado for three straight games, the first two at home beginning on Thursday.
- Calgary D Rhett Warrener returned after missing three games with an arm injury.
- RW Tony Amonte also came back from a benching on Sunday, the first game he missed all season. Amonte has no goals in 14 games.
- Flames C Stephane Yelle (foot) didn't play.
- De Vries played in his 142nd consecutive game, tying him with Slava Kozlov for the longest streak in Thrashers history.
- Calgary is 4-0 against Atlanta.