Giroux was inferring that the Flyers needed to set the tone against a Bruins team that entered the night tied for the most points in the NHL.
But despite Giroux's plea, the Flyers came out flat. Again. They continued a recent trend: falling behind early and chasing the game.
They fell into a 2-0 first-period hole before Kevin Hayes answered with a power-play goal late in the period.
In the last nine games, the Flyers have been outscored in the first period, 18-8, which is not a recipe for success in the Scotty Bowman Handbook.
The Bruins struck first after a Phil Myers turnover put goal-scoring sequence in motion. Anders Bjork got behind Myers and put a backhander past Carter Hart, who overcommitted on the play and the
With 3:11 left in the first, Krejci got behind Ivan Provorov and tapped in Danton Heinen's perfect goal-mouth pass, putting the Bruins ahead, 2-0. It gave Boston power plays goals in 14 straight games, an ongoing franchise record.
Hayes, converting a slick feed from Konecny, scored on a one-timer from deep inside the right circle while the Flyers were on a power play, slicing the Bruins' lead to 2-1 with 1:38 to go in the first.
The Flyers' defense has been pristine at the Wells Fargo Center this season -- allowing a league-low 1.90 goals per home game -- but they continued to have breakdowns in the second period as the Bruins built a 5-2 lead.
Thirty-three seconds into the second, David Pastrnak, after a bad pinch by Provorov, took a feed from Brad Marchand and made it 3-1 by scoring his league-best 36th goal.
Sanheim, aided by Michael Raffl's screen, answered 39 seconds later to cut the lead to 3-2, but Boston then scored two goals in a 2:31 span to make it 5-2.