Acquired from Dallas this week shortly before the trade deadline, Jagr joined the Bruins for the pregame skate Thursday morning and quickly endeared himself to the Boston fans. Brad Marchand's centering pass went off Jagr's left skate and past Martin Brodeur to give the Bruins a 1-0 lead with 80 seconds gone in the second period.
Fans, some wearing mullet wigs, gave Jagr a standing ovation when he took the ice for his first shift in the first period and chanted his name after the goal.
Rask earned his third shutout of the season. Brodeur made 25 saves for the Devils.
The Bruins keep pace with Montreal, which entered the night with a one-point lead in the Northeast Division. New Jersey, the defending Eastern Conference champions, fell into ninth and out of playoff position when the New York Islanders went into overtime with the Capitals on Thursday.
Jagr, 41, is 10th on the NHL career list with 1,680 points over a 19-year career in which he established himself as a star alongside Mario Lemieux with the Pittsburgh Penguins while winning the Stanley Cup in his first two seasons. After stints with the Capitals, Rangers, Flyers and Stars, Dallas sent him to Boston on Tuesday for two prospects and a draft pick.
His presence became even more important for the 2011 Stanley Cup champions when first-line center Patrice Bergeron sustained a concussion on Tuesday night - at least the fourth of his NHL career. Bergeron, who leads the Bruins with 31 points in 35 games, is out indefinitely.
Jagr took the ice on Boston's second line with Marchand and Tyler Seguin. In addition to his somewhat inadvertent goal, he whiffed on a backhand with an open shot at the net midway through the second period, and had another open net in the third, when his sweeping shot was blocked by a sprawling defenseman.
The Devils' best chances came in the second, when Dainius Zubrus and David Clarkson hit the crossbar in succession. New Jersey had some good shots on Rask after pulling Brodeur in the final minutes, but Boston was able to protect the lead.
Notes: The Bruins have beaten the Devils six consecutive times. ... After Zubrus and Clarkson hit the crossbar in the second period, the Boston fans responded by chanting Rask's name. ... Jagr and Brodeur were both drafted in 1990. Jagr was the No. 5 overall pick by the Penguins and Brodeur was taken 20th by the Devils.