It was the first game for the Sabres since Terry Pegula officially became the fourth owner of the team Tuesday. Pegula and his son dropped the ceremonial first puck prior to the contest.
Buffalo had lost its previous three games.
Andrew Ladd scored Atlanta's only goal early in the second and the Thrashers went on to lose for the eighth time in nine games. Ondrej Pavelec allowed all four goals on 39 shots.