DENVER — Matt Duchene's scoring slump and the Colorado Avalanche's third-period struggles contributed to a slow start for both.
Those issues were solved for at least one night.
Duchene scored twice, his second 1:28 after Nathan MacKinnon broke a 3-3 tie late in the third period, and the Avalanche beat the Calgary Flames 6-3 on Tuesday night.
Duchene broke out of a seven-game scoring slump, and Jarome Iginla also had a pair of goals for Colorado. Iginla added an assist against his former team.
"We needed that one," Duchene said. "We've been working really hard and going through some stuff."
Duchene's offensive struggles coincided with his team's slow start for the second straight season. Colorado entered 1-4-1 at home, in part because of its inability to finish close games in the third period.
"Five of our seven losses we go into the third period up or tied and we end up losing. That just can't happen if you want to be a playoff team," Duchene said. "That's something we have to get over."
It was another close one until MacKinnon scored from the slot at 13:01 of the third. Duchene scored on a tip-in to make it 5-3.
Iginla scored into an empty net at 17:11, but it was his win along the boards to set up MacKinnon's winner that bothered the Flames.
"That's the story of the start of our season right now," Flames coach Bob Hartley said. "We lost the battle on the wall, 3-3 game and the puck's in our net. That's where it is. We have to get dirtier in critical areas and critical times of the game. That's why we lost."
Johnny Gaudreau, Sam Bennett and Mark Giordano scored for the slumping Flames. Calgary has won just twice in its last 11 games.
The Flames rallied to tie it at 7:34 of the third when Giordano's shot went off Avalanche defenseman Francois Beauchemin and bounced through Semyon Varlamov. It was his fourth of the season.
Varlamov made 22 saves for the Avalanche.
Colorado responded with three unanswered goals. The Avalanche finished with 42 shots.
"It was a different feeling," MacKinnon said of the third period. "We knew how we felt when we collapsed. Tonight it was different, more confidence. We just knew we were going to win this game. We thought we deserved it and we went and took it, so it definitely feels good."
After Gaudreau tied it early in the second, the Avalanche took a 3-1 lead on goals by Iginla and Erik Johnson. Johnson scored his third of the season on Calgary's only power play of the first two periods.
Johnson had a goal and an assist.
"I was screaming, screaming, screaming to (Beauchemin) to give me the puck," Johnson said of his goal. "He zipped it across and I got a quick slapper off and put it over the glove. Any time you can get a contribution short-handed it boosts the team, and I'm just happy to get the win. There's nothing better than winning."
Bennett scored his second of the season at 18:33 of the second to cut it to 3-2 heading into the third. He had another goal waved off when the official ruled the puck was covered up by Varlamov in the crease.
The Flames had another goal disallowed when it was ruled the puck crossed the line after the net was knocked off its moorings.
"I looked at the replays," Bennett said. "It is frustrating, but I think the refs made the right call."
Duchene gave Colorado a 1-0 lead with 22 seconds left in the first period with his second goal of the season. He put in his own rebound just inside the right post.
NOTES: Colorado D Tyson Barrie had three assists. ... Avalanche C John Mitchell (oblique injury) did not play. Colorado recalled C Ben Street from San Antonio of the AHL to take his place in the lineup. ... The Flames have allowed five short-handed goals in their last five games. ... Iginla's goals were his first against his former team. He has 595 career goals overall.