David Pastrnak scored a hat trick Saturday against the Pittsburgh Penguins, and he became the No. 2 single-season scorer in team history.

The Bruins defeated the Penguins 4-3 in Pittsburgh, and Pastrnak's quick shot from the slot with less than 3 minutes to play in the third period provided the margin of victory.

That goal was Pastrnak's 56th of the season, allowing him to bypass Cam Neely, who scored 55 goals for Boston in the 1989-90 season. The only Bruins player to exceed 56 goal in any season is Hall of Famer Phil Esposito.

He passed that mark 4 times, including his team-record 76 goals during the 1970-71 season. Esposito was one of the mainstays of the Big, Bad Bruins in the late 1960s and early 1970s before he was traded to the New York Rangers in 1975.

The hat trick was the second of the season for David Pastrnak and the 14th of his career. His first goal was a deflection of a shot from the point by Dmitry Orlov on the power play in the second period that gave the Bruins a 2-1 lead. His second goal was a hard wrist shot in the third period that broke a 2-2 tie.

The win allowed the Bruins to improve their record to a dominant 59-12-5. The Bruins clinched the Presidents Trophy for best regular-season record earlier in the week and they still have a chance to earn the most wins of any team in a season. The current record is 62, held by Detroit Red Wings and the Tampa Bay Lightning.

The loss hurts the Penguins, who sit in the No. 2 wild card position and are trying to hold off the Florida Panthers for the last playoff spot in the Eastern Conference.