The Bruins’ banner-raising ceremony figured to be the most memorable part of Thursday night for the B’s, and the Flyers made sure of it by defeating the Bruins, 2-1, in the season-opener.

The Bruins took a 1-0 lead in the first period when Tyler Seguin set up a Brad Marchand power play goal. The Flyers got on the board with a power play goal of their own thanks to Claude Giroux in the final minute of the first period, and Jakub Voracek made it 2-1 with less than three seconds remaining in the first.

Both the Bruins and the Garden crowd appeared tired by the time the second period had rolled around, and after a scoreless second, the B’s woke up in the third period. The first line, which was nonexistent through the first two periods (see below) woke up, but an improved third-period effort wasn’t enough to mount a comeback.

Tim Thomas amide 27 saves for the Bruins, while Ilya Bryzgalov stopped 22 shots.

WHAT WENT WRONG FOR THE BRUINS

- Pretty sloppy first game for the top line of Milan Lucic, David Krejci and Nathan Horton. Each had their bright spots, as Krejci nearly set up a Brad Marchand goal during a line change, but collectively the line didn’t get into much of a rhythm and failed to connect on its passes. The line didn’t have a shot on goal until the third period and was a minus-1.

With less than 10 minutes remaining, Horton failed to bury an opportunity in front with an open net. He took too long upon catching the pass from Krejci, and eventually had his bid blocked by the stick of Kimmo Timonen. Krejci nearly tied the game with les than five minutes to go, as Bryzgalov accidentally dropped the puck in the crease after Krejci’s wrist shot, but he covered it before the center could get to it.

- The members of the first line weren’t the only Bruins to fail to get pucks on Bryzgalov. The Bruins had just six shots on goal in both the first and second periods. The only forwards with multiple shots on goal were Marchand (3) and Seguin (2).

- Kelly missed the net on a 2-on-1 with Seguin in the first period. The new co-aletnerate captain played well in centering the new-look third line, but he won’t get easier opportunities than that. Given that the Bruins would lose a low-scoring game, a blown opportunity like that looks even worse.

WHAT WENT RIGHT FOR THE BRUINS

- Power play woes were the norm last season until the B’s went 5-for-27 on the man advantage against the Canucks. On Thursday, the new-look second unit of Joe Corvo, Patrice Bergeron, Marchand, Tyler Seguin and Rich Peverley yielded Marchand’s first period tally. Seguin hit Marchand with a long pass from just outside the neutral zone to set up Marchand. The B’s ended up a modest 1-for-5.

- Speaking of Marchand and Seguin, they were two of the best players on the ice Thursday. Marchand had plenty of scoring opportunities, as he undressed Chris Pronger in the second period before Bryzgalov poked the puck away. The Flyers’ netminder robbed Marchand again later in the period with a glove save in front.

As for Seguin, there was a lot to like about his line with Chris Kelly and Jordan Caron. The second-year player looked much more assertive than he was in his rookie season, and he created opportunities in areas where he may have been timid a season ago. Keep an eye on that line going forward.