When the Bruins went shopping for some defensive talent in the offseason, they envisioned winning games like they did on Saturday night in Detroit.

The B’s allowed just 19 shots on Jeremy Swayman, got the third-period game-winner from captain Brad Marchand and they choked out the Red Wings for a 2-1 victory.

Since Joe Sacco took over from Jim Montgomery as head coach earlier in the week, the B’s penalty kill (4-for-4 for the second straight game) and overall defensive game has been markedly better. They’ll need to start scoring some more goals, but the B’s are indeed taking care of the most important things first.

Both teams scored once in an evenly played first period.

One lineup change that was made was the insertion of Tyler Johnson after Georgii Merkulov was sent down to Providence. Johnson was also put on the second power-play unit and it paid off at 8:33 with the B’s on the man advantage.

Johnson took a pass from Mason Lohrei in the right circle and he wasted no time scouting his options. He quickly fired it to the net, where Justin Brazeau tipped home his fifth goal of the season.

On the next shift, Johnson shot the puck in the crowd and the B’s had to go on the kill, something that hasn’t performed very well, especially on the road. But against Detroit’s dangerous PP unit (30.2% going into the game), the B’s did a good job of keeping the Wings to the outside to kill the infraction.

While Detroit held a slight territorial advantage and the B’s were not crisp, especially on their breakout passes. But the B’s did not give up much inside their zone.

That was until the final minute of the period, when the Wings tied it up. Brazeau, appearing to have banged up his left arm, was slow getting back into the defensive zone on a Detroit rush. Lucas Raymond took the open space in the high slot and rifled home a Vladimir Tarasenko pass past Jeremy Swayman with 57.4 seconds showing on the clock.

The B’s had to kill off two more Detroit power plays in the second period, which they did well, though on the first one they needed a good Swayman pad save on Andrew Copp in tight.

The B’s, who also had one fruitless power play in the second, had perhaps their best scoring chance on the penalty kill on a late Parker Wotherspoon penalty. On a shorthanded 2-on-1, Brad Marchand fed Pavel Zacha, but Zacha appeared to fan just a bit on the shot and Cam Talbot was able to make the save.

The second period was the B’s 10th straight period without a 5-on-5 goal. They had some chances that never even got to Talbot. One glittering opportunity came when David Pastrnak found himself all alone with the puck low in the left circle in a 3-on-2 situation. But as he looked around for his options, the Wings were able to recover and he never got a shot off.

That streak would be snapped at 11:30 of the third period.

After a questionable icing call brought the draw back into the Detroit zone, the B’s controlled the puck. Andrew Peeke came down low to gather a Pastrnak pass in the right circle. He dish it off to a circling Marchand, who sniped a wrist shot over Talbot’s glove shoulder, his sixth of the year.

The B’s had to kill one more penalty when Marchand took a hooking call with 1:22 left to give the Wings a 6-on-4 with the goalie pulled.

But the B’s came up with some big faceoff wins to make it another perfect 4-for-4 on the kill and secure Joe Sacco’s second win in as a many games as head coach.