Tage Thompson had a goal and an assist, and Peyton Krebs, Jack Quinn, and Owen Power each had two assists for the Sabres (3-3-0), who lost their previous two games. Ukko-Pekka Luukkonen made 13 saves after entering in the second period for Colten Ellis, who allowed two shots on nine shots.
Dahlin, the Sabres captain, left in the second after taking a slap shot from the edge of the right face-off circle at 3:29. He headed for the locker room shortly thereafter and did not return.
Buffalo visits the Montreal Canadiens on Tuesday, the start of a three-game road trip.
Sam Reinhart scored twice, and Brady Tkachuk got his first point for the Panthers (2-2-2), who have lost four of five (1-2-2). Jacob Markstrom allowed two goals on 11 shots before exiting after the first period. Akira Schmid made 18 saves in relief.
Florida visits the Columbus Blue Jackets on Tuesday.
Ostlund gave the Sabres a 4-3 lead with a power-play goal at 7:15 of the third, when Zach Benson found him in front of the net for a quick one-timer.
Josh Doan put Buffalo in front 1-0 at 5:58 of the first. He received a pass from Krebs on the rush at the Panthers blue line and took it to the right circle, where he beat Markstrom with a wrist shot.
Anton Lundell tied it 1-1 at 11:00. Ellis made a chest save but couldn’t contain the rebound, and Lundell won a puck battle low in the right circle and slipped it between Ellis’ pads.
Dahlin made it 2-1 on the power play at 15:55 with a one-timer from above the slot that got past Markstrom high to the blocker side.
Reinhart tied it 2-2 with a power-play goal at 6:26 of the second. Seth Jones’ shot from the middle of the blue line trickled between Ellis’ pads, and Reinhart reached to poke it across the line for his first goal of the season.
Luukkonen relieved Ellis after the goal.
Ryan McLeod gave the Sabres a 3-2 lead at 11:25 when he broke in and deked Schmid before sliding a wrist shot past the goalie’s skate.
Reinhart scored on the power play again at 13:41, capitalizing on a between-the-legs backhand pass from Brady Tkachuk at the far side of the net to tie it 3-3.
With the assist, it was Tkachuk’s first point in six games with Florida after being acquired in a trade from the Ottawa Senators on June 23.
Thompson took a feed from Power and beat Schmid blocker side from the slot at 13:20 of the third for the 5-3 final.
