David Pastrnak celebrates with teammates as fans throw hats on the ice after Pastrnak’s third goal of the game – and 60th of the season – during a 5-3 win Sunday against the Philadelphia Flyers. Chris Szagola/Associated Press

PHILADELPHIA — David Pastrnak posed with the puck he used to score his 60th goal of the season in front of the whiteboard in the locker room that had “63 WINS” written in blue marker.

It’s not the Boston Bruins’ biggest goal, but they now own the NHL single-season wins record, thanks to their best player putting on a show.

Pastrnak recorded a hat trick to reach 60 for the first time in his career, leading the Bruins to their 63rd victory of the season, 5-3 over the Philadelphia Flyers on Sunday night. The win broke a tie with the 1995-96 Detroit Red Wings and 2018-19 Tampa Bay Lightning.

“It’s been a lot of fun, I’m not going to lie,” Pastrnak said after his fourth four-point game this season. “It’s been enjoyable, especially the group we have here. We obviously knew the stakes, and it’s definitely special to hit it in a game like this. Made history today in the biggest league in hockey.”

Hats rained down from the many Bruins fans in attendance after Pastrnak scored his third of the game early in the third period. The crowd chanted “We want the Cup!” in the final minutes, then showered players with cheers at the final horn.

“It’s hard to win in this league and there’s a reason why this record (was) at 62, because not many teams can get there, so it’s a special honor,” said goaltender Jeremy Swayman, who made 34 saves. “These guys in this room are more than deserving.”

The Bruins have won six in a row and have 131 points, one shy of the record held by the 1976-77 Montreal Canadiens, and with two games left against opponents well out of the playoff race. Boston will have home-ice advantage throughout the playoffs in pursuit of the franchise’s first Stanley Cup championship since 2011.

Boston rested its top two centers, Patrice Bergeron and David Krejci, along with No. 1 defenseman Charlie McAvoy, forward Taylor Hall, key trade deadline pickup Dmitry Orlov and All-Star goaltender Linus Ullmark.

Even with a lineup chock full of players from the AHL’s Providence Bruins, Boston relied on a familiar recipe to set the wins record. Beyond Pastrnak’s goals, Charlie Coyle and Pavel Zacha scored, Jeremy Swayman made 34 saves, and the Bruins extended their streak of consecutive penalties killed to 38.

“They had some people out, but still that’s a really good hockey team,” Flyers Coach John Tortorella said.

The Bruins also kept up what first-year coach Jim Montgomery called their “signature calling” of closing out games. After allowing a goal to Owen Tippett midway through the third period, the Bruins locked things down, as they have so many times before, improving to 46-1-2 when leading at the second intermission.

Pastrnak joined MVP favorite Connor McDavid as a 60-goal scorer, making this the first season with two players reaching that mark since Mario Lemieux and Jaromir Jagr in 1995-96. The Czech winger had 48 goals when the pandemic ended the 2019-20 season, so that gave him the belief he could put together a season like this.

“I know what kind of player I am in this league right now,” Pastrnak said. “I knew I could do it. That helps with your mindset.”

Pastrnak is just the second player in franchise history to score 60 goals – Phil Esposito did it four times – and he became the eighth player to score 300 career goals with the Bruins.

Wade Allison and Joel Farabee also scored for the Flyers, who lost their seventh in a row late in another lost season. Felix Sandstrom made a few big stops among his 29 saves, but that wasn’t enough to slow down the Bruins.