Duchene, Seguin each has 3 points to lift Stars past Bruins

BOSTON -- Matt Duchene and Tyler Seguin each had a goal and two assists for the Dallas Stars in a 5-2 win against the Boston Bruins at TD Garden on Thursday.

Mason Marchment had two assists, and Casey DeSmith made 25 saves for Dallas (6-2-0). Jason Robertson scored in his 300th NHL game.

“There was a quiet confidence in the group,” Stars coach Pete DeBoer said. “We had no passengers tonight. I thought everyone was engaged and involved, and a real good team. Probably our best team game of the year.”

The Stars scored three power-play goals in the second period, which tied a team record for the most in a period since the franchise moved to Dallas in 1993.

“It’s exciting to see some power-play goals go in,” Seguin said. “We’ve been working hard at it, probably gripping our sticks too much at it. … We’ve just been working through it, and it’s nice to see some results for the players.”

David Pastrnak and Justin Brazeau scored, and Jeremy Swayman made 27 saves for Boston (3-4-1), which has lost three straight (0-2-1).

“If you’re not focused on habits and details, you’re going to get frustrated,” Bruins coach Jim Montgomery said. “The margins of error aren’t very big in this league. And we’re on the wrong side right now, and I think our attitudes are driving it.”

Pastrnak gave the Bruins a 1-0 lead at 11:57 of the first period during 4-on-4 play. Matthew Poitras intercepted Stars defenseman Mathew Dumba’s pass behind the net before setting up Pastrnak for a one-timer in the slot.

“We came out slow, and we can’t wait until the second half of the game to find our legs and find a way to push,” Poitras said.

Duchene tied it 1-1 at 16:20 of the first, taking Seguin’s cross-ice pass wide and elevating the puck past Swayman from the left face-off circle.

“We wanted to get back to Dallas Stars hockey,” Duchene said. “Every single guy was going tonight. Even when we got down one [goal], we really liked our 5-on-5 game in the first [period], and we just want to keep going.”

Robertson gave the Stars a 2-1 lead 31 seconds into the second period, finishing off Jamie Benn’s behind-the-net feed on the power play.

Logan Stankoven scored his first of the season to make it 3-1 at 4:57. Duchene skated in unimpeded down the left side and found Stankoven in front for another power-play goal.

“We've got to stop taking penalties, and that’s myself included," Bruins defenseman Charlie McAvoy said. "… Most of the time, you can always draw it back to effort. We’re taxing our penalty kill way too much.”

Seguin pushed it to 4-1 with the Stars' third straight power-play goal at 8:59. He beat Swayman with a wrist shot after he was left open with plenty of space on the right side.

Brazeau cut it to 4-2 at 10:41, finishing off Trent Frederic’s wraparound attempt for his own power-play goal.

“When everybody’s playing the right way, usually everyone enjoys success and benefits from it,” Bruins captain Brad Marchand said. “We’re kind of right around it, and it’s going to come. But us as leaders and older guys, we need to be better and we need to set the tempo for that and kind of lead by example.”

The Bruins outshot the Stars 10-7 in the third period, but Roope Hintz scored an empty-net goal for Dallas at 17:58 for the 5-2 final.

“When you’re trying to hold on to a lead, it’s tough because the other team brings everything they have,” DeSmith said. “Not that we sat back, but playing a little bit more careful and calculated. So, I just thought they were a little bit desperate and they brought it in [the third] period.”

NOTES: DeBoer won his 618th game in the NHL, passing Bruce Boudreau and Jacques Lemaire for sole possession of 21st place on the all-time list. ... It was Hintz's 400th NHL game. ... Dallas had been 2-for-21 on the power play through its first seven games before going 3-for-5 on Thursday. ... Marchand has not scored a goal through eight games this season. It’s his longest season-opening goal drought since 2010-11, when it took nine games to score.