Anton Khudobin made 25 saves and Patrice Bergeron netted the winner early in the third period as Boston got by Buffalo, 3-1, on Sunday.
Khudobin, who only has nine NHL appearances to his credit, improved his career record to 7-1-0, including wins in both of his 2013 starts.
"It was great. I just had to stop a couple [shots] to keep it scoreless," Khudobin said. "The guys played awesome in front of me."
Brad Marchand and Milan Lucic also tallied for the Bruins, who have won three in a row and six of their last seven.
Tyler Ennis recorded the lone goal for the Sabres, who had taken a 7-4 decision in Boston on Jan. 31 in the clubs' first meeting.
Ryan Miller played well in defeat, stopping 36 shots.
"I think we started to show our fatigue around the midpoint," Miller said. "They're a tough team to play against and they certainly were going to make it so we weren't going to have the opportunity to score as many goals as we did last time."
Bergeron put the Bruins ahead at the 7:52 mark of the third period while on the power play. He alertly beat a pair of Sabres defensemen to a puck which caromed off the end boards and back out into the left circle, and beat Miller high to the glove side.
Miller was called to the bench for an extra attacker in the final minute, and Lucic potted the insurance marker into the empty cage.
Buffalo was given a brief advantage when Boston defenseman Andrew Ference was called for high sticking 14 seconds later, but failed to convert.
In a scoreless opening period, both goaltenders were sharp, with Khudobin making 13 saves and Miller answering with 16 stops.
The Sabres successfully killed a two-man disadvantage early in the second period, but the Bruins took a 1-0 lead when Marchand's wrister from the left circle hit the back of the net at 7:10.
Ennis knotted the game inside of two minutes left, drawing Khudobin to the side of his crease before lifting a shot home from the left side.
Bergeron's winner was his second goal this season and first since Jan. 25 against the New York Islanders ... Lucic posted his first goal since a Jan. 23 loss to the New York Rangers ... Sabres forward Thomas Vanek was held off the scoresheet for only the second time in 12 games ... Buffalo defenseman Tyler Myers was listed as a healthy scratch.