The Bruins flexed their front line skill in their big win over the Colorado Avalanche on Thursday.

On Saturday against the Montreal Canadiens, the B’s threw their surging depth scoring at their ancient rivals to run away from the Habs in the third period in a 9-4 win at the Garden.

Danton Heinen notched his first career hat trick (goals 6, 7 and 8) and 16 of the 18 skaters found their way onto the scoresheet.

Montreal was game to start, but the Habs’ defense was just not up to the task.

It was clear from the start that the Habs at least wanted to put up a fight, and for a while they did. In the opening minutes, the defense tandem of David Savard and Mike Matheson each landed a big hit on David Pastrnak on the same shift.

Montreal also took two separate one-goal leads but the B’s went into the first intermission with a 3-2 advantage.

The Habs took the first lead of the game at 9:18 on the power play when Cole Caufield beat Linus Ullmark (in his first start since suffering a lower body injury on January 9) from the side of the net after Mike Matheson made a great play to keep the puck in at the blue line.

The B’s answered back at 12:47 on a nice give-and-go between Brandon Carlo and Trent Frederic, with Frederic dishing at back to the defenseman for the redirection goal (3) in his first game back from a concussion.

But the B‘s were playing a little looser than they had been recently and the Habs regained the lead off the rush with Joshua Roy connecting with Joel Armia for the go-ahead goal at 15:00.

The B’s, however, answered with a pair of goals in 55 seconds.

The first one was derived from good, hard work along the boards. James van Riemsdyk knocked a puck loose from a Hab defender along the end boards for Jake DeBrusk, who simply took the puck to the side of the net and jammed it through goalie Sam Montembeault at 18:10. It was the 11th goal of the season for the percolating DeBrusk

Before the period was done, Danton Heinen gave the B’s their first lead of the game when he redirected a beautiful slap pass from Matt Grzelcyk from the left point.

The B’s could not shake the Habs in the back-and-forth second.

With Charlie Coyle in the box for high-sticking, the Habs made it 2-for-2 on the power play, with Matheson beating Ullmark with a high slot shot at 6:16.

Montreal was feeling it, especially after Michael Pezzetta took another run at Pastrnak that was a hair late but allowed. Tempers eventually boiled over into a Trent Frederic-Josh Anderson scrap, for which Anderson got the extra two for roughing.

The B’s couldn’t cash in on the power play, but again they blitzed the Habs with a pair of goals in less than a minute.

Heinen scored his second of the game (7) when Jesper Boqvist sprung him for a 2-on-1 with Matt Poitras. Heinen elected to take the shot sizzled a far-side wrister 10:46.

Then 49 seconds later, Pastrnak made a great pass to Coyle from the high slot that the centerman deflected past Montembeault. It was Coyle’s 16th of the season.

But if the B’s thought they’d put Montreal away, they were mistaken. After the B’s failed to clear the zone on several chances, Brendan Gallagher stuck with a puck in front of the net and managed to get his second chance shot through Ullmark’s pads at 13:19.

After the B’s killed off the second half a Grzelcyk penalty to start the third period, Pastrnak gave the B’s their two-goal lead again at 1:26 of the period on a partial break. Wearing defenseman Jayden Struble on his left hip, Pastrnak got one shott off on Montembeault and then scored on his own rebound for his 30th goal of the season, the seventh time he’s reached that plateau.

That finally broke the Habs. The B’s pushed the lead to three on a momentous goal from Brad Marchand, his 20th of the year off a Coyle feed. It marked his 11th straight 20-goal season, pushing ahead of Patrice Bergeron and Johnny Bucyk.

Pavel Zacha made it a laugher with his 10th of the season and 100th career goal before coach Jim Montgomery put Heinen on the ice for a power play. Morgan Geekie found him for the hatty and the goood times were rolling.