Joe Nieuwendyk netted a third-period, power-play goal and Nathan Horton scored in the second period for the Panthers, who won for the second time in seven games. It was Florida's second road win of the season (2-6-3).
Glen Murray scored his team-leading 10th and 11th goals for Boston, which had its longest winning streak since March 2004 stopped.
Tim Thomas, making his fifth straight start for the Bruins, stopped 25 shots.
The Bruins cut the deficit to 3-2 on Murray's second goal with 5:04 to play, but Boston couldn't get the tying goal despite pulling Thomas for an extra skater for the final 1:06. The Bruins didn't even record a shot with Thomas out.