Mark Letestu scored and Marc-Andre Fleury turned aside 29-of-30 shots for the Penguins, who remained two points behind Eastern Conference-leading Philadelphia while improving to 5-6-4 in their last 15 games.
Pittsburgh ran its winning streak over the Sabres to six games.
Rob Niedermayer scored for Buffalo, which lost in regulation for the first time in eight games.
Ryan Miller turned aside 28-of-31 shots for the Sabres, which remained in possession of the eighth and final Eastern Conference playoff spot.
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