Zach Benson and Mattias Samuelsson each had two assists, and Alex Lyon made 24 saves for the Sabres (15-14-4).
Noah Cates, Cam York and Travis Konecny scored, and Bobby Brink had two assists for the Flyers (17-10-6), whose five-game point streak ended (2-0-3). Samuel Ersson made 23 saves.
Jack Quinn gave Buffalo a 1-0 lead at 7:40 of the first period when he redirected Samuelsson’s point shot past Ersson’s left skate.
Cates scored 58 seconds later to tie it 1-1 at 8:38. Brink took a loose puck into the left face-off circle and pushed it over to Cates, who beat Lyon glove side with a quick snap shot from above the left hash marks.
York put Philadelphia ahead 2-1 at 11:01 of the second period. He received a pass from Trevor Zegras in the right circle and scored to the far side.
Thompson tied it 2-2 at 16:54. Rasmus Dahlin sent a backhand pass through his legs to Thompson in the right circle, and Thompson cut toward the hash marks before beating Ersson far side.
Thompson has five goals during his streak.
Noah Ostlund gave Buffalo a 3-2 lead at 19:30, taking a pass from Owen Power and sending a wrist shot through traffic.
Josh Norris pushed it to 4-2 at 10:20 of the third period with a power-play goal. Benson found him uncovered in the right circle for a wrist shot that beat Ersson through the five-hole.
Konecny cut it to 4-3 at 14:28, going blocker side from above the slot, before Ryan McLeod scored an empty-net goal at 19:52 for the 5-3 final.
