Tanguay scored with a man advantage in the second period and Semyon Varlamov stopped 29 shots, helping the Avalanche hold off the Calgary Flames 3-2 on Saturday night.
Ryan O'Reilly and John Mitchell also scored for the Avalanche, who went 2-1 on a three-game homestand to remain in the playoff chase. They have a few days off before embarking on a five-game trip.
Colorado entered the game last in the league at home on the power play. But Tanguay made sure the team capitalized on the only chance it had in the game, banking in a shot from an improbable angle.
"We were due to get a bounce coming our way and fortunately for us it went in," said Tanguay, who also had an assist against his former team. "It's a huge win."
Also, another huge performance by Varlamov as he remains unbeaten in his last five starts. He made a crucial stop in the waning seconds to secure the win for Colorado, which moved to within five points of the last wild-card spot in the Western Conference with 13 games remaining.
David Jones and Lance Bouma scored for the Flames. Karri Ramo made 23 saves as he filled in for Jonas Hiller, who played the night before in a 6-3 win against Toronto. Calgary is 5-2-1 and holding onto a playoff spot after losing top defenceman Mark Giordano for the season because of a torn biceps tendon.
"We do miss (Giordano) and every guy is trying to improve their game a little bit more — pulling the rope a little bit harder," said Jones, who was a little dinged up on a third-period check that sent him into the boards. "A little bit of a speed bump tonight. But we'll jump back."
The Flames pulled Ramo with about 1:30 remaining for an extra skater, but Colorado's defence clamped down and didn't allow many good scoring chances.
Jones cut the deficit to 2-1 early in the third period when he accidentally kicked in the puck with his skate on a pass from Mikael Backlund. Just 28 seconds later, Mitchell restored the two-goal lead. But that didn't last long, either, with Bouma lining a slap shot over Varlamov.
Colorado was able to kill off a late penalty and Varlamov made a sensational save on a shot by Raphael Diaz with 5:09 remaining. Falling to the ice, Varlamov reached back and corralled the puck with his glove.
"We knew they're a resilient team and they certainly battled back in the third period," Mitchell said. "So they clawed their way back in, but we held the fort and stood our ground."
Calgary was called for too many men on the ice midway through the second period and Tanguay scored when he banked in a shot off the pads of Ramo. Asked about what he thought of the penalty after the game, Calgary coach Bob Hartley simply said, "There's nothing to think about. It's over. Obviously, we think way differently, but that's the way the game is."
Just 1:47 later, Tanguay sent a pinpoint pass over to a charging O'Reilly, who lifted a wrist shot over the glove of Ramo. It was O'Reilly's first goal since Feb. 3 at Dallas.
Joe Colborne nearly had a goal with 31 seconds remaining in the first period when the puck trickled into the net. But officials ruled that Varlamov couldn't play his position and signalled no goal. The play wasn't subject to review.
Colborne also banged Varlamov in the head on the play, which Varlamov didn't take kindly to and shoved him back. That touched off a skirmish between Josh Jooris and Tyson Barrie.
"We knew how difficult it was going to be," Tanguay said. "We knew it was almost like a Game 7. This is a team we are chasing so we are in a desperate situation. Certainly those points are welcome."
NOTES: Calgary F Mason Raymond played in his 500th NHL game. ... Backlund had two assists. ... Colorado D Tyson Barrie had two assists. ... Avs F Jarome Iginla had an assist against Calgary. He played 15-plus seasons for the Flames and remains the team's career leader in points (1,095), goals (525) and games played (1,219).