Boston goaltender Linus Ullmark makes a save in the first period Monday night against St. Louis at Boston. Charles Krupa/Associated Press

BOSTON — Patrice Bergeron scored a power-play goal with 7:15 remaining and the Boston Bruins beat the slumping St. Louis Blues 3-1 on Monday night.

Trent Frederic and Jake DeBrusk also scored for Boston, and Brad Marchand had two assists. Linus Ullmark finished with 25 saves as the Bruins improved to 7-0 at home and won for the eighth time in nine games overall.

“It wasn’t necessarily their best or our best but it was one of those things where it was a grind of a game and we found a way to get through it,” DeBrusk said.

Brayden Schenn scored and Jordan Binnington had 34 saves in the Blues’ seventh straight loss – all in regulation.

With the score tied 1-1 deep into the third period, St. Louis captain Ryan O’Reilly was whistled for tripping with 8:28 left to put the Bruins on the power play, and they capitalized.

Binnington stopped two shots by Marchand and managed to cover a rebound during an extended scrum in front of the net. However, the Bruins won the faceoff and worked the puck around to Bergeron in the slot for a one-timer that put Boston back on top with his fifth of the season.

“I think it’s always fitting that Bergeron comes through,” Bruins Coach Jim Montgomery said. “There’s not enough words that I can say about how much he means to the team culture and to the team productivity. He’s a player that gets the job done night in and night out.”

Frederic helped seal it with 3:32 left with his third.

The Blues had a pair of power-play opportunities in the first eight minutes of the game but couldn’t capitalize, finishing with just five shots on goal in the period.

“We just didn’t create enough momentum for the team in the first period. The second period, we were better. I thought the whole night we worked, we competed,” Schenn said. “In the D-zone, we got running around there in the third. They kind of took it to us quite a bit obviously and they were able to capitalize and win the game.”

The Bruins led 1-0 after DeBrusk scored on a power play with 6:26 left in the first period, taking a backhand feed from David Pastrnak in the slot and slipping it between Binnington’s legs for his fifth.

Schenn tied it for St. Louis on a one-timer with 8:23 left in the second off a crossing pass from Jordan Kyrou. It was his third. Former Bruins defenseman Torey Krug also assisted on the goal.

The Bruins scored on both of their power-play opportunities and killed off all three chances when the Blues had the advantage.

“The effort’s there. We showed up tonight. We competed hard. That’s a good team over there,” Schenn said. “We’ve just got to find a way to score goals and get the results we want.”