PITTSBURGH — The sluggish opening three months. The so-so finish. The only occasional attention to detail on defence. None of it matters anymore.

The playoffs are here. The champs are, too.

Sidney Crosby and the Penguins provided proof in Pittsburgh's 7-0 dismantling of the Philadelphia Flyers in the opening game of their first-round series Wednesday night.

Crosby performed more stick wizardry on his way to his third post-season hat trick, Evgeni Malkin added a highlight-reel goal of his own and the Penguins overwhelmed their seemingly overmatched cross-state rivals to begin their quest for a third straight Stanley Cup with a blowout that seemed to indicate the grudge match could be a mismatch.

Not that Pittsburgh's captain wanted to buy into any sort of message sending, even after the Penguins became only the fifth team in NHL history to win a series opener by at least seven goals.

"I mean, it's one game," Crosby said. "Whether it's 7-0 or 1-0 or double overtime, it's one game. A big part in the playoffs is to get better every game and to adjust, and that's the way we have to look at it."

That might be a frightening proposition for the rest of the NHL. It certainly is for the Flyers, who have lost all five meetings with Pittsburgh this season, giving up at least five goals each time. Nothing that happened during the regular season, however, compared to Wednesday night. The Penguins pumped five goals in the first 29:01 to chase goalie Brian Elliott, and the Flyers simply could not keep pace.

"It was one of the worst games I've been a part of," Flyers forward Claude Giroux said.

Philadelphia coach Dave Hakstol mercifully pulled Elliott after Crosby swatted Brian Dumoulin's point shot out of the air and knocked it by a stunned Elliott to put the Penguins up 5-0 just before the game's midway point. Elliott stopped 14 of 19 shots before being replaced by Petr Mrazek. Mrazek made 12 saves, but Hakstol indicated he's likely to go with Elliott again in Friday's Game 2.

Whoever is in net for the Flyers, it won't matter if the play in front of them isn't better. Philadelphia's power play went 0 for 4 and didn't even generate a shot.

"They beat us from pretty much every aspect tonight, starting from the net out," Elliott said. "Everybody just has to be better."

Jake Guentzel had a goal and three assists for Pittsburgh. Bryan Rust and Carl Hagelin also scored. Matt Murray stopped 24 shots for his third straight playoff shutout.

The Flyers stressed the need to stay out of the penalty box and put together three disciplined, competitive periods if they wanted to put an abrupt halt to Pittsburgh's run at history. It didn't happen. Not even close.

The Penguins jumped on Philadelphia early. Elliott stopped Kris Letang's slap shot with his blocker only to see the long rebound go right to Rust, who ripped it over Elliott's right shoulder to give the Penguins the lead 2:38 into the game.

Philadelphia's best chance at staying in it came minutes later, but Scott Laughton whiffed on his first attempt from the doorstep and Murray made a sprawling glove save on Laughton's second try to preserve Pittsburgh's lead.

"If that goes in, it's 1-1 and maybe we're talking about a different result," Crosby said.

Moments later, Hagelin expertly redirected Patric Hornqvist's shot past Elliott 10:07 into the game. Malkin drew a hooking penalty to negate a Pittsburgh power play, and when he emerged from the penalty box, he whizzed past three Flyers in one sequence, darting by Jakub Voracek, slipping past Giroux and then fending off Shayne Gostisbehere before flicking a backhand past Elliott to put the Penguins up 3-0 before the series was 15 minutes old.

All that before Crosby got involved.

The two-time MVP has a knack for scoring in unorthodox ways. He beat Montreal's Carey Price with an intentional double-deflection and smacked a rebound out of air in overtime to top New Jersey within a span of eight days last month.

His first of the playoffs was just as impressive and provided the exclamation point on a night Pittsburgh looked every bit the threat to become the first team since the New York Islanders of the early 1980s to capture three straight Cups.

NOTES: Crosby's hat trick tied Pittsburgh owner and Hall of Famer Mario Lemieux for the most post-season hat tricks in franchise history. ... Murray hasn't allowed a goal since Game 4 of the 2017 Stanley Cup finals, a span of 206:26. ... The Penguins, who had the league's top-ranked power play during the regular season, went 1 for 4 with the man advantage. ... Pittsburgh C Derick Brassard, who missed time late in the regular season with a lower-body injury, had an assist in 13:44. ... Injured Steelers LB Ryan Shazier, who is recovering from spine stabilization surgery and has already been ruled out for the 2018 season, stood up and led the sell-out crowd in a pre-game cheer.

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