VANCOUVER — Johnny Gaudreau wasn't overly concerned as the officials gathered at the penalty box Monday night, conferring over whether or not the Calgary Flames forward had, in fact, scored the overtime winner.

The 27-year-old winger had put a puck past Vancouver Canucks goalie Thatcher Demko just 23 seconds into overtime after the Flames blew a 3-2 lead in the final minute of regulation.

Then the men in stripes came together and decided that Toronto needed to review whether Gaudreau's goal had been offside.

It wasn't.

“I looked at the replay, it looked pretty good. We were talking about it on the bench," Guadreau said after Calgary's 4-3 overtime win was confirmed.

"Sometimes it goes either way and it went our way tonight.”

Canucks winger Brock Boeser forced extra time in dramatic fashion, sniping a shot past Jacob Markstrom with 30.2 seconds left on the clock.

It was a short-handed tally as defenceman Quinn Hughes sat in the box. Vancouver pulled Demko in a desperate bid to salvage the game.

“It just shows that we have no quit. Even when we're down a guy and pull the goalie and get one and get that extra point. It's good for our team," said Boeser, who also had an assist on Monday.

"Obviously we make a few mistakes and if we don't make those, I think we win the hockey game, so I think overall we still played a good game but some small details we've got to fix."

Monday's matchup was the third in a four-game series between the two sides. Saturday saw the Canucks take a 3-1 victory over the Flames.

It was a loss that didn't showcase Calgary's true identity, Gaudreau said.

“We’re very capable of playing a solid 60-minute game. Obviously, on Saturday, that wasn’t the team we know we are," he said. "We had a real good practice yesterday and I thought we played a real strong second and third period (tonight.)”

Monday's showing was closer to the game the Flames want to play, said coach Geoff Ward.

“I thought we were much, much better tonight," he said. "Definitely a step in the right direction.”

The Canucks (7-11-1) held a two-goal lead near the end of the first period Monday but saw the game start to slip away on a series of costly mistakes.

Milan Lucic sparked the Flames' comeback with 24 seconds to go in the opening frame, ripping a shot past Demko from high in the slot to make it 2-1.

Elias Lindholm added a breakaway goal off a blue-line turnover and Dillon Dube capitalized on another mistake midway through the second frame.

Vancouver defenceman Nate Schmidt put the puck on Dube's tape instead of clearing it from behind the net and the Flames forward tucked a shot in behind Demko's skate before the netminder could even register the misstep.

Dube said his line has been wreaking havoc on opponents by forechecking hard.

“I think for us right now, when we play that game, there’s skill on that line, but if we play hard, create turnovers, then we get the puck," he said. "It’s simple for us, we’re direct.”

Rasmus Andersson had a pair of assists for the Flames (8-6-1), just one of the burgeoning defenceman who Ward said put in solid performances on Monday.

“There’s an awful lot of young guys here," the coach said. "I thought they did a good job back there for us tonight. These are the types of games you learn from.”

Markstrom stopped 30-of-33 shots, while Demko had 23 saves for the Canucks.

Tanner Pearson and Bo Horvat also scored for Vancouver.

The ultimate difference Monday was that Calgary capitalized on its chances, Pearson said.

"It's what these games are gonna come down to, especially when the long haul starts," he said. "It could be a real battle, especially when we play these teams over and over. It becomes kind of playoffs so there's not much room."

NOTES: Vancouver defenceman Tyler Myers had two assists. … Calgary's Connor Mackey registered an assist on Lucic's goal, marking the first point of the 24-year-old defenceman's NHL career. … Mikael Backlund did not play after for the Flames suffering a lower-body injury on Saturday.

This report by The Canadian Press was first published Feb. 15, 2021.