Many believe a two-goal lead is the most dangerous in hockey.
Others contend a three-goal edge has that distinction.
Truth is, the game's most dangerous lead might be any that the Penguins get against Philadelphia at Consol Energy Center. Doesn't matter how large, or how they get it.
Getting in front of the Flyers here rarely is a problem. Staying there, as they were reminded in a 6-5 loss Wednesday night, is considerably more difficult.
Or, much of the time, impossible.
They built early leads against the Flyers in Games 1 and 2 of their first-round playoff series against the Flyers here last spring, but lost both and were jettisoned into the offseason in six games.
And that script held against Wednesday night, when the Penguins, winners of their previous three games, built a 2-0 lead in the first seven minutes, 15 seconds, then watched the Flyers run off four unanswered goals en route to their sixth victory in seven regular-season visits to Consol Energy Center.
The twist this time was that the Penguins actually rallied from a two-goal deficit late in the third period, only to lose when Flyers forward Jakub Voracek completed a hat trick by putting a shot off goalie Tomas Vokoun and into the net from behind the goal line with 91 seconds left in regulation.
"I knocked it in my own net," Vokoun said. "That's tough. I think the guys battled hard to tie the game. That's tough. That's a bad break. Sometimes, that's the way hockey is. It's really disappointing."
Which also is how the Penguins felt about the elbowing minor Craig Adams was serving when Voracek broke a 2-2 tie with 9.9 seconds left in the second period. He had been sent off after a run-in with Voracek a 18:28.
"I was very surprised," Adams said. "I thought maybe he got it."
Regardless of the legitimacy of the penalty on Adams, the Penguins routinely allowed themselves to be drawn into scuffles that worked to Philadelphia's advantage.
"We got too emotional in the game, too involved with the extracurriculars down the line," Penguins coach Dan Bylsma said. "It took away from the game.
"That was something they needed, something they got involved in and got energy going their way. We knew it was a tactic they were going to use."
Matt Niskanen put the Penguins up, 1-0, when he drove a shot through a Brandon Sutter screen and past Flyers goalie Ilya Bryzgalov at 5:07.
Evgeni Malkin made it 2-0 on a power play at 7:15, collecting the carom of a Paul Martin shot off the back boards and tossing it in from the right side of the crease.
That goal, Malkin's first in six games, extended the Penguins' streak of games in which they have gotten at least one man-advantage goal to nine.
The Flyers pulled to within one at 11:49 after an extended scrum, during which virtually everyone on the ice except Bryzgalov was in or around the Penguins crease, as defenseman Nicklas Grossmann flipped the puck through the tangle of bodies and into the net.
Wayne Simmonds tied the score exactly one minute later, taking the puck to the net and sweeping it past Vokoun from the edge of the crease.
That was the last goal for either team until late in the second, when Voracek put the Flyers in front.
It didn't take long for Philadelphia -- and Voracek -- to get another as he capped a scramble in the Penguins end by scoring from between the right circle and the crease just 18 seconds into the third.
The Penguins finally ended the Flyers' run when Tyler Kennedy converted a Martin rebound at 5:29 -- the goal was Kennedy's first in 15 games, while Brooks Orpik's assist gave him the first three-game scoring streak in his 602-game NHL career -- but the Flyers quickly went back up by two.
Simmonds made it 5-3 when his shot from near the left dot glanced off Niskanen's stick and sailed past Vokoun at 7:36.
James Neal got Penguins within one during an extended five-on-three power play at 12:46, and Sutter swept in a shot from the left side of the crease at 17:57 to pull them even.
Just 32 seconds later, however, Voracek got the game-winner to complete a story line that has become all too familiar for the Penguins, who seemed nearly as unhappy with how the game unfolded as with how it ended.
"It was not the type of game we want to play, a 6-5 game," Adams said. "Whether we win it or lose it."
Dave Molinari: Dmolinari@Post-Gazette.com or Twitter: @MolinariPG. First Published February 21, 2013 5:30 AM