Zacha pushed the Bruins lead to 2-0 on the power play at 12:48, deflecting Morgan Geekie’s pass up and in from the right side of the net.
Marchand extended it to 3-0 at 18:25, taking Charlie Coyle’s pass into the middle and lifting the puck to the top right corner with his backhand.
“We feel good about our group,” Marchand said. “I mean, we have all year. We added two tough pieces, two great guys in the room [Pat Maroon and Andrew Peeke before Friday’s trade deadline]. … Love our group, feel very confident in it and come playoff time, anything can happen, and we have a group we believe in and that’s what’s important.”
Letang cut it to 3-1 at 2:51 of the third period with a slap shot from the left point, but DeBrusk made it 4-1 off a cross-ice pass from Marchand at 9:36.
“We had some looks pretty early and throughout the game,” said Pittsburgh forward Michael Bunting, who made his Penguins debut after arriving as part of the trade package from the Carolina Hurricanes in exchange for Jake Guentzel on Thursday.
“Obviously they’re right there, and we want to be able to capitalize on those looks.”
Zacha forced the puck past Nedeljkovic at the net front at 15:33 of the third for the 5-1 final.
NOTES: Pastrnak reached 40 goals in a season for the third year in a row. He has scored in two straight games after not scoring in the previous four. … Ullmark had lost each of his previous six starts before Saturday, but five came in overtime or a shootout. … Zacha extended his point streak to four games (five goals, two assists).