Voracek scored his first goal late in the second period and then put the Flyers 4-2 up early in the third as Philadelphia (8-9-1) took control of the Atlantic division battle.
However, the Penguins fought back, tying the game at 5-5 in a see-sawing third period before Voracek sealed the win for the Flyers with his sixth goal of the season.
Pittsburgh, who were eliminated from last season's playoffs by the Flyers, opened strongly and took a 2-0 lead early in the first through Matt Niskanen and Evgeni Malkin.
Goals from Nicklas Grossmann and Wayne Simmonds tied the score in the opening frame before two from Voracek put the Flyers 4-2 up.
Tyler Kennedy, James Neal and Brandon Sutter scored to get Pittsburgh back into the game, while Philadelphia's Simmonds also netted in the third.
With the score tied at 5-5, Voracek put the finishing touches to his stellar night with a game-winning wrist shot at 18:29.
The outcome gave the Flyers a second straight victory while the Penguins (11-6-0) had their three-game winning streak snapped.
"Never know what's going to happen, it's always up and down when we play Pittsburgh," Flyers wing Wayne Simmonds told reporters. "It seems like it's last team that scores, wins."
Pittsburgh coach Dan Bylsma lamented his team's inability to maintain focus throughout the encounter.
"We got too emotional in the game, too involved with the extracurriculars and it took away from our game," he said.
The Penguins had a chance to take over the Eastern Conference lead with a win. Instead, they remain tied at the top of the Atlantic Division with New Jersey on 22 points.
Voracek stayed hot for the Flyers after he also tallied four assists Monday against the New York Islanders.
On the downside, Philadelphia lost goals leader Matt Read to an upper-body injury. He did not return after the first intermission and the team said Read would be evaluated on Thursday.
(Writing by Jahmal Corner in Los Angeles; Editing by Peter Rutherford/John O'Brien)