Johnny Boychuk and David Krejci scored within 1 win over Buffalo and giving the Bruins their first back-to-back victories in almost two months.
Boychuk scored 12:56 into the period on a shot from the far right side to snap a 1-1 tie and Krejci's goal in transition at 15:54 gave Boston its 3-1 lead.
The Bruins scored three unanswered goals after falling behind late in the first period. Coming off a win at Toronto on Tuesday, they earned consecutive victories for the first time since beating Winnipeg and Montreal on Jan. 10 and 12.
Tim Thomas had 19 saves for the Northeast Division leaders, including 14 over the last two periods, and Gregory Campbell had the other Boston goal.
"We worked hard tonight, even in the final minutes to finish it off and get the two points," said Thomas.
Jason Pominville scored for the Sabres, who fell 13 points behind Boston in the division and remain on the outside looking in for a playoff spot in the Eastern Conference. Jhonas Enroth gave up three goals on 28 shots.
Boychuk was in the right place at the right time for his go-ahead goal -- skating into the right circle, where a loose puck was there for a rifled slap shot that beat Enroth to the near side.
Bruins captain Zdeno Chara started the rush that ended in Krejci's goal at the other end, clearing the zone with a crisp pass. Krejci got behind two Sabres defenders and Milan Lucic found him with a pass through the slot.
Thomas had eight saves in the second period and six in the third after giving up a goal on six shots in the first.
Pominville gave the Sabres a 1-0 lead with 3:21 left in the opening period after he carried the puck down the right and beat the Bruins goaltender glove- side with a slap shot from the circle.
Campbell tied the game for Boston with 1:51 remaining in the second, getting a piece of Shawn Thornton's slap shot from the point and tipping it out of mid- air past Enroth from the slot.
Buffalo had won the last two meetings this season and six of its previous eight games against Boston before Thursday...The Bruins, who are No. 2 in the Eastern Conference, remain home to play Washington on Saturday...The Sabres stay on the road to play Ottawa on Saturday...Both teams were 0-for-1 on the power play.