"It's the battle of Pennsylvania," Hartnell said. "It was a big measuring game. It was intense and we played well enough to win."
Pittsburgh center Evgeni Malkin returned after missing four games with a knee injury, and scored two goals to give him 10 for the season.
Crosby assisted on both of Malkin's goals, extending his point streak to 19 games. He has 20 goals and 18 assists in matching his career-long streak from Oct. 6-Nov. 17, 2007. Crosby has 62 points (26 goals, 36 assists) in 36 career games against Philadelphia.
"You never like losing and just because we won however many we won doesn't change that feeling, and I don't think it ever will," Crosby said. "You go out there and you work hard and you have an objective in mind to win a game and you don't -- so no, it's not a good feeling. Luckily for us we have a game [Wednesday] night, so we can look to respond."
Claude Giroux and Nikolay Zherdev also scored for the Flyers, who have won five of six games to vault into first place in the Atlantic Division. Philadelphia (20-7-5) also leads the NHL with 45 points.
The Dec. 14 date is the earliest that Philadelphia has reached 20 wins in a season since 1986.
The Penguins hadn't lost since a 3-2 overtime defeat to the New York Rangers on Nov. 15.
"It doesn't matter how many you win, losing is not where you want to be," Penguins coach Dan Bylsma said. "We're disappointed in the first period in particular. Philadelphia dictated the pace."
The mid-December meeting carried a playoff-type atmosphere for the sellout crowd of 19,824.
The Penguins came into Philadelphia as the league's second-best penalty killing team on the road, but gave up a power-play goal in the third period. They had difficulty staying out of the penalty box, and many of their infractions came shortly after game-tying goals, making it difficult to gain any momentum.
"We got to a point where we draw even, and we spent a lot of energy killing penalties against dangerous guys," Bylsma said. "It also took our team away from trying to get to the offensive zone and mount any kind of pressure. It took away from us in the third period."
"I parked myself in front of the net and I was able to get my stick on it," Hartnell said.
Philadelphia snapped Fleury's personal-best 11-game win streak, and the Penguins' goalie entered the game 13-0-1 in his past 14 games against the Flyers. He finished with 34 saves.
Flyers coach Peter Laviolette stayed with hot goaltender Brian Boucher, who stopped 21 of 23 shots to move to 5-0-1 in his past six games. Boucher had turned away 66 of 68 shots in wins over Toronto and Boston.
Boucher faced a flurry of shots over the final 2:26, including 2 minutes of a Penguins' power play set up by a goalie interference call on Darroll Powe. They gained possession about a minute into the power play, but couldn't connect.
The Flyers outshot Pittsburgh 37-23.
"It would have been nice if we would have buried one there to make it 4-2," Boucher said. "Instead we take the penalty for drama points and make it a nail biter for the fans, but it was a great kill there at the end. "
Giroux gave the Flyers a 1-0 lead at 12:32 of the first, putting a rebound from a Danny Briere shot past a sliding Fleury for his 15th goal of the season. Hartnell also had an assist on the goal. Seconds before, Fleury lost his stick behind the net.
Zherdev scored his 10th goal of the season, giving Philadelphia a 2-1 lead at 12:28 of the second. Taking a pass from James van Riemsdyk, he skated between the faceoff circles and flipped a shot past Fleury.
Malkin tied the game twice for the Penguins. His first goal came at 8:23 of the second, on a one-timer from just inside the blue line.
His second came at 3:18 in the third, on a shot from just outside the slot, through a Matt Cooke screen during a 4-on-3 power play, and through Boucher's legs.
"Cooke was in front of me, but [Malkin] beat me high before, so I was thinking high there," Boucher said.
The Flyers hung on for the win and moved to a league-best 8-1-1 in their division, and beat the Penguins for the third time this season.
"We talk about trying to be the best in the league, and tonight was one of those opportunities where we could do it ourselves and didn't have to have help," Laviolette said. "It puts you where you want to be, but you can enjoy it for about three minutes and move on to start thinking about [the next game]."
In the most recent fan balloting results for the All-Star game, Crosby holds a commanding lead in overall votes with 410,754. ... Flyers left wing Jody Shelley served the first of a two-game suspension for a hit from behind on Boston Bruins defenseman Adam McQuaid during Saturday's game. ... Philadelphia goalie Michael Leighton was recalled from his conditioning assignment, with defenseman Ian Laperriere (concussion) moving to long-term injured reserve.