The tail end of the Bruins’ 18-game point streak was a grind. That was obvious on many fronts, perhaps none as telling as giving up their first goal for eight consecutive games and squeaking out several comeback wins.

Sure, the streak had to end eventually — especially with the loss of Brad Marchand and Charlie McAvoy. But it was the nature of the snapping — a near-direct result of the five-shot first period the Bruins produced against the Ducks on Tuesday — that couldn’t hide behind an excuse.

That’s when the fog of the team’s longest point streak since 1969 gave way to what had been the reality all along. Just because the Bruins could keep finding ways to battle back didn’t mean the scenario was ideal.

After Thursday’s 3-1 win over the Blues, Bruce Cassidy joked that the Bruins “just got sick of losing.” The bounce back effort — yes, that’s what it was — wasn’t about the scoreboard, and the loss to Anaheim was actually a blessing not-so-in-disguise. Even if a win is a win, and the final result was never an indication through the point streak, the Bruins had to change their mentality.

“I think it’s been around seven or eight games when other teams scored first. You don’t want to start like that…ever,” left winger Jake DeBrusk said pregame.  “We need to get on the board here first tonight and go from there.”

DeBrusk’s eight shifts in the first matched the urgency of his words. His transition game, pressure and takeaway went unrewarded until he shot at Jake Allen’s net. That sparked a wild sequence of net-front events, and a loose puck David Krejci put away to end the Bruins’ three-game first-period scoring drought at 12:32.

“That was our focus. Get the first goal,” Krejci said postgame. “It was really close [goaltender interference], but sometimes you need bounces to go your way and it was one of those nights.”

That first period won the game as much as Tuesday’s lost the previous.

The difference was on display for all to see, as the Bruins dominated puck possession throughout the second. Krejci dangled, Torey Krug dangled. They crept up and stole the shot advantage. Allen, however, gave the B’s absolutely nothing while at even strength. He faced 45 shots and stopped a season-high 43.

All the more reason why that first-period effort mattered beyond boosting morale.