Those early puck drops often lead to sleepy starts, and that was certainly the case for the Bruins, who played the first 20 minutes as if someone had replaced their doubles with triples.

Matvei Michkov, on the other hand, had plenty of caffeine in his young legs and scored twice in the first game, giving the youngster his 11th goal of the young season.

The Bruins couldn’t capitalize on an early decision to have too many men on the ice, although Brad Marchand had a good chance, but his tip of Charlie McAvoy’s blue-line bid went just wide.

Marchand was sideswiped by Philadelphia defender Cam York, but the referees overlooked the clear interference violation, much to the Boston captain’s chagrin. Instead, Mark Kastelic was whistled for dumping Egor Zamula at center ice at 7:13.

The Flyers only needed 11 seconds to take advantage of the power play. Michkov was in the circle to the left of Jeremy Swayman (23 saves) and scored on a rebound from Sean Couturier in the penalty area for a 1-0 lead.

York finally found his way to the box when he beat Johnny Beecher 20 seconds after Michkov’s goal.

The Bruins pushed forward on the power play, with David Pastrnak setting up Marchand at the crease that Aleksei Kolosov (27 saves) smothered, and one from Zacha at the left point that bounced high over the glass.

Zacha had another good attempt later, but his snapper off a feed from Justin Brazeau landed off the right post.

A poor, unremarkable backhand cleanup attempt by Jordan Oesterle led to the Flyers’ second goal.

Travis Sanheim grabbed the puck and pounced on it, sliding it to Michkov at the left post, and the baby-faced assassin hammered it in for a 2-0 lead after a minute.

The Bruins had more room to maneuver against the Bauers early in the second round, but were still down by two (3-1) after 40 minutes.

Boston cut the deficit to 2-1 after 5:26 with a power play goal from Trent Frederic.

Just seconds after Kolosov overwhelmed Morgan Geekie with a one-timer, Frederic swept in a rebound from Mason Lohri’s shot that hit Sanheim in front and fell directly onto the winger’s stick. It was Frederic’s fourth goal of the season.

Couturier got away with an interference call when he dropped Pastrnak in the neutral zone, which led to Sanheim’s wrister that Swayman flashed with the glove. After the whistle, Pastrnak approached Couturier to express his dissatisfaction.

Philadelphia restored its two-goal lead by taking advantage of a tired Boston team that was on an extended shift in its own zone. Sanheim sent the ball to York, who had sneaked through the slot and pushed a ball past Swayman, who was dealing with a screen provided by Couturier.

Towards the end of the middle phase the physicality increased. Charlie McAvoy tripped Michkov and then charged toward the tower, apparently dissatisfied with how easily he hit the deck. It sparked a minor riot that resulted in McAvoy and Owen Tippett, who were defending Michkov, hitting rough minors.

Jim McBride can be reached at [email protected]. Follow him @globejimmcbride.