Seguin went to his knees and pumped both fists in the air after scoring his fifth goal of the season off a pass from rookie Wyatt Johnston. Just before that, Seguin had fallen down after whiffing on a puck near the corner.
Nils Lundqvist tied it at 3 with 5:06 left in regulation on a shot through traffic from outside the circle to the left of Ottawa goaltender Anton Forsberg. That came immediately after Roope Hintz won a faceoff.
Miro Heiskanen scored twice in less than two minutes to give Dallas a 2-0 lead in the first period. Lundqvist assisted on the second of those goals. The Stars were coming off their first shutout loss of the season two nights earlier.
Forsberg and Stars goalie Jake Oettinger both made 28 saves. Forsberg faced one more shot, the game-ender.
Derick Brassard, Thomas Chabot and Travis Hamonic scored for the Senators.
Hamonic gave Ottawa its only lead at 3-2 when he got his stick on the puck in front after Alex DeBrincat’s shot only 87 seconds into the third period. That was soon after Dallas had killed off a penalty that carried over from the second.
It was the first two-goal game this season for Heiskanen, but the standout defenseman was also on the ice for both Ottawa goals later in the first period. His turnover in the Stars zone led directly to the first one.
Brassard scored from the slot on a pass from Drake Batherson after he got the puck from Heiskanen.
The Senators got even at 2 on Chabot’s hard shot that deflected off a Dallas player and went in just under the crossbar with 1:13 left in the first.
NOTES: Hintz and Johnston each had two assists. … Heiskanen has nine points (three goals, six assists) in his last five games. … Jason Robertson was held without a point for the second game in a row since an 18-game point streak that set a Dallas record. … The Senators won four of five games before losing their last two.
Ottawa stays on the road to play Nashville on Saturday.
Dallas wraps up a five-game homestand Saturday against Detroit.