Rookie center Brad Marchand scored on a power-play rebound with 3 minutes, 43 seconds left to snap a 1-1 tie. Both of the Bruins' goals were scored on rebounds shortly after the Flyers went to the penalty box.
Brian Boucher stopped a point drive by former Flyer Dennis Seidenberg, but Marchand pounced on the rebound and deposited his 20th goal. Mark Recchi, another former Flyer, also notched an assist.
Within a 10-second span with about 16 minutes left in the third period, Boston goalie Tim Thomas made a pair of key stops on Jeff Carter out front to keep the score tied at 1. Thomas began the night leading the NHL with a 2.02 goals-against average and a .938 save percentage.
With Boucher pulled for an extra attacker, the Flyers applied some late pressure, but Thomas foiled James van Riemsdyk's rebound attempt with 1:04 to go.
Thomas made 27 saves; Boucher made 34.
It's difficult to watch a Flyers-Bruins game and not think back to last year's stunning Eastern Conference semifinals. The Flyers, of course, became the third team in NHL history to overcome a three-games-to-none series deficit.
In their first three meetings against the Flyers this season, the Bruins went 2-0-1, extracting a tiny bit of revenge.
On Sunday, the Flyers were trying to solidify their hold on first place in the conference and Atlantic Division - and send a message to the Bruins in case the teams meet again in the playoffs.
The Flyers struck first as Kris Versteeg became the sixth player on the team to reach 20 goals, although 14 of his tallies were scored with Toronto.
Mike Richards took a pass from van Riemsdyk - who hustled to get to the puck and keep it in the zone - and wound up to take a slap shot. Instead, Richards deftly fed Versteeg to the left of the net, and the winger one-timed it past an out-of-position Thomas with 15:15 left in the first period.
"It was all them on the goal," said Versteeg, referring to his linemates. "I was just the recipient of two good plays."
With 12:20 remaining in the second period, however, Boston scored the equalizer four seconds after Blair Betts went to the penalty box for tripping.
David Krejci won a faceoff from Richards and sent the puck back to Tomas Kaberle at the point. Kaberle's drive was stopped by Boucher, but Nathan Horton knocked the juicy rebound into the net to tie the score at 1.
Boston, which had a 14-7 shots edge in the second period and shut down the Danny Briere line, was trying to extend its first-place lead to seven points over fading Montreal in the Northeast Division.
Contact staff writer Sam Carchidi at email@example.com. Follow on Twitter at www.twitter.com/BroadStBull.