Boston’s Taylor Hall celebrates his goal in the second period Wednesday night against the Washington Capitals, in Washington. Nick Wass/Associated Press

WASHINGTON — Jim Montgomery wanted the Boston Bruins to show who they have, not who they don’t have, to start the season.

Turns out who they have, even missing two key players to injury for quite some time, is still pretty good.

David Pastrnak had a goal and three assists, captain Patrice Bergeron scored and Boston beat the Washington Capitals 5-2 on Wednesday night to give Montgomery a victory in his Bruins coaching debut. Bergeron got the puck for Montgomery – a former UMaine standout – after the final horn, a symbol of the first accomplishment in a long season.

“It’s going on the mantle, probably in my son’s room,” said Montgomery, who was working his first NHL game as a head coach since Dec. 7, 2019. “It feels great, but more importantly, we do this together. And it’s an honor to lead that group.”

Without winger Brad Marchand and No. 1 defenseman Charlie McAvoy, whose absences were considered long term after offseason surgeries, the group still clicked a lot like the Bruins who made the playoffs each of the past six seasons.

It doesn’t hurt to have Pastrnak playing at his best: assisting on Bergeron’s power-play goal with the initial shot that turned into a juicy rebound and setting up Taylor Hall with a perfect pass into the middle of the ice to put Boston up 3-0. Washington scored twice before Pastrnak took the shot that turned into David Krejci’s sealing goal with 3:43 left.

“He’s growing each year,” said Krejci, who had a goal and two assists in his first game back in the NHL after playing last season in his native Czech Republic. “He’s just a world-class player. It’s crazy. That guy has no ceilings. He just keeps getting better.”

Krejci’s return to North America coincided with Bergeron coming back for a 19th season with the Bruins, which he got off to a nice start by scoring his 401st career goal.

Montgomery is back running an NHL bench less than three years after he was fired by the Dallas Stars for unprofessional conduct. He sought and received help for alcohol abuse, spent time as an assistant in St. Louis and is getting another chance with Boston.

Linus Ullmark, who figures to rotate starts with former UMaine goalie Jeremy Swayman in net for Boston, made 33 saves, including a flashy grab with his glove to rob Evgeny Kuznetsov early in the third period.

“He was awesome,” Montgomery said. “He battled hard. He fought for every rebound. He was really good for us.”

Darcy Kuemper struggled a bit in his Capitals debut less than three months since backstopping the Colorado Avalanche to the Stanley Cup. Kuemper allowed four goals on 29 shots, giving up a big rebound to Bergeron and getting beat five-hole along the ice by Pastrnak.

“Other than that, I felt pretty good about my game,” Kuemper said. “Obviously not happy with the result.”

Anthony Mantha and Conor Sheary scored for Washington, which went 0 for 4 on the power play. Captain Alex Ovechkin, the active leader in goals in season openers, had three shots on net but was held off the score sheet.

Coach Peter Laviolette acknowledged some disconnects in his team’s game, on the power play and beyond.

“We were disjointed, it seemed, for the first half of the game and when you wanted the puck to be there, it wasn’t,” Laviolette said. “We weren’t on the mark with the pass or we weren’t on the mark with positioning or we got outnumbered in a battle. Whatever it might be, we just weren’t clicking. We weren’t in sync.”

Hampus Lindholm scored an empty-netter with 1:05 left.

NOTES

Montgomery had no update on forward Jake DeBrusk, who left the game after the second period. … Czech F Jakub Lauko made his NHL debut for the Bruins wearing No. 94. It’s the highest number a player has worn in the nearly-100 year history of the Original Six franchise. … Boston signed veteran defenseman Anton Stralman to a $1 million contract for the season, and he will be eligible to play when his work visa is settled.

• President Cam Neely said that team chef Keith Garman died unexpectedly at age 33. A cause of death was not provided, and it was not clear where Garman was when he died.

Bergeron called it a “horrible, horrible day” for the Bruins learning of Garman’s death and said players were shocked and saddened.

“His work ethic, really, is the first thing that comes to mind when I talk about chef Keith,” Bergeron said. “He was there at the crack of dawn to cook us the best meals, and always had a smile on his face. You always had a conversation with him. In the house, you’re always drawn to the kitchen, right? It was the same thing with him in his kitchen.”

Neely said Garman “worked tirelessly to make a positive impact on everyone around him.”