Observations from the Bruins’ 2-0 win over the Flyers

Defenseman Matt Grzelcyk (left) celebrates with teammates after his second-period goal Tuesday.Drew Hallowell/Getty

PHILADELPHIA – Their backline missing their No. 2 pairing, the Bruins Tuesday night survived a sluggish first two periods thanks to Tuukka Rask’s sharp netminding, and pinned a 2-0 defeat on the Flyers here at Wells Fargo Center.

Matt Grzelcyk broke a 1-0 deadlock, firing home a power-play goal, his first this season, late in the second period.

Patrice Bergeron then provided the Broad Street crusher, snapping in a long wrist shot off the rush with 5:20 remaining in regulation.

With the win, their 44th this season, the Bruins became the first team in the NHL this season to reach 100 points in the standings (44-14-12).

It’s the third consecutive season they have reached 100 with Bruce Cassidy behind the bench.

Brad Marchand picked up the primary assist on Bergeron’s goal (No. 31), extending his scoring streak to 13 games.

The Bruins, now with 12 games remaining the regular season, next play Friday night in Buffalo.

The loss ended a nine-game undefeated streak for the Flyers.

Rask, on his 33rd birthday, finished with 36 saves and improved his record to 26-8-6 with his fifth shutout this season.

Some observations from the victory:

▪ The Bruins were badly outshot, 24-14, over the first two periods, but nonetheless carried a 1-0 lead into the final period.

The only goal of the opening 40 minutes came on a power-play, Matt Grzelcyk rocketing in a 50-foot one-timer form the center point off of a one-time touch pass from David Pastrnak with 1:21 left in the second.

It was the first power-play goal this season for Grzelcyk, seeing time on the power play in part because Torey Krug exited the lineup after being injured Saturday vs. Tampa.

▪ Frustrated with his lack of offense, coach Bruce Cassidy made radical changes to his forward line combinations as the midpoint of the second period approached.

David Pastrnak vacated his No 1 right wing spot, with speedy newcomer Ondrej Kase moving up with Brad Marchand and Patrice Bergeron.

David Krejci soon found himself with two new wingers on the No. 2 line, with Pastrnak on his right and surprise left sider Sean Kuraly.

All of that left Charlie Coyle riding between Nick Ritchie (LW) and Jake DeBrusk (RW).

▪ Less than a minute prior to Grzelcyk’s go-ahead strike, Coyle made the play of the night after losing the puck along the right wing wall at his offensive blue line. With the Flyers bolting up ice on a 2-on-0, the streaking Coyle sprinted back and made a perfectly timed dive to bust up a Scott Laughton dish intended for Kevin Hayes at the right post. A dynamic recovering, and approximately 45 seconds later Grzelcyk drilled in the 1-0 lead.

▪ Neither side put a puck in the net over the opening period. The Flyers, winners of nine in a row, went 0-for-2 on the power play and peppered Tuukka Rask with a dozen shots but could not connect.

▪ The Bruins, hampered in part buy having to kills two penalties (Wagner, Marchand) managed only eight shots on net and did not really test Flyers tender Carter Hart.

▪ The Broad Streeters, trying for decades to find an answer to their net, appear to have that answer in the 21-year-old Hart. He put up a solid rookie season (16-13-1) and has rebounded with a better season — albeit behind a team vastly improved with the addition of Alain Vigneault behind the bench.

▪ The Flyers entered the night with nine straight wins, with a lopsided 39-17 scoring edge over that stretch. They also were 8-for-25 (32 percent) on the man-advantage, despite going 0-for-5 in the previous two games.