VANCOUVER, British Columbia — Johnny Gaudreau knows that Saturday night could have turned out much differently. That's just life in the NHL's new 3-on-3 overtime format.
Gaudreau had the puck on his stick in the Vancouver zone seconds before the winner, but lost it to Vancouver forward Brandon Sutter, who was poised to send Daniel Sedin in on a breakaway.
But Sutter in turn lost it to Calgary defenseman Dennis Wideman, and the puck found its way back to Gaudreau, who made no mistake in beating Ryan Miller.
"Definitely nerve-wracking," Gaudreau said of the 3-on-3 OT format. "With so much time and space and ice, one costly turnover or mistake and that's the game. You've got to be smart out there. You have to be strategic about it, but it's fun."
Calgary coach Bob Hartley said Gaudreau, who also had two assists, wants to be a difference-maker every time he's on the ice.
"You can't teach to be great in big moments. This guy's got it," Hartley said. "Every time I see that he has the puck on his stick I feel that we have a chance to win. That's who he is and that's how he plays."
Dougie Hamilton and Sean Monahan scored in regulation for the Flames, while Jonas Hiller made 28 saves.
Bo Horvat and Jared McCann, with his first NHL goal, scored for the Canucks, who got 35 saves from Miller.
The teams played in Wednesday's season opener, which Vancouver won 5-1 in Calgary.
"I thought that this was the Calgary Flames," Hartley said. "Third period, we were skating well. I thought our puck possession was real good. Then in OT, well, just open the floodgates and just watch."
Down 2-1 after two periods, the Flames tied it at 8:49 of the third after the Canucks turned the puck over in their own zone. Calgary forward Jiri Hudler found Monahan in front, and he buried his first of the season past Miller.
"We quit getting the puck deep. We turned it over," Canucks coach Willie Desjardins said. "We'd go cross-ice or we'd dump to their (defense), and they kept coming after us. When you do that eventually they are going to get something."
Gaudreau had a great chance from the slot with just over 90 seconds to play in regulation, but Miller made the save.
Hiller made a couple of big saves in the extra period before Gaudreau's winner, including a glove stop on Sedin.
"It's kind of like an all-star game," Hiller said. "You've got to be pretty much ready for anything. It's kind of fun, but at the same time it's definitely not the kind of game you want as a goalie."
McCann gave his team a 2-1 lead at 11:33 of the second, taking a pass from Jannik Hansen after the Flames couldn't get the puck out and ripping a shot high over Hiller's glove in just his second NHL game.
The 19-year-old forward nearly jumped out of his skates in celebration, smashing into the boards with excitement before being mobbed by teammates.
"I almost blacked out to be honest," McCann said. "It was a great feeling, but obviously it would have been nice to end the way we wanted."
Vancouver trailed 1-0 after the first, but tied things up at 2:03 of the second period on the power play. After rookie defenseman Ben Hutton made a nice play at the Calgary blue line, Horvat took the puck hard to the net. His initial shot was stopped, but he collected the rebound in a maze of legs and settled himself before firing a shot high over Hiller for his first of the season.
The 20-year-old Horvat is expected to have an increased role in his second season and is currently centering both the second line and second power-play unit.
The Flames, who beat the Canucks in six games in the first round of last season's playoffs, opened the scoring exactly five minutes into the first period on the power play.
Gaudreau took a pass at the side of the Vancouver net before feeding Hamilton, who beat Miller from the face-off circle for his first point with the Flames.
The defenseman was acquired in an off-season trade with the Boston Bruins and signed a contract extension with Calgary through 2020-21.
"Our guys responded well," Hartley said. "I thought (Hiller) gave us a huge game in net, as did Miller on their side. It was great goaltending on both parts and both teams battled hard."
Note: Vancouver D Alexander Edler missed the game because of illness. Yannick Weber took his spot in the lineup. ... Calgary was 10-20-4 when trailing after 40 minutes last season.