The Wild’s defense took a day off on Saturday in Philadelphia, pummeled by a struggling Philadelphia team that came out flying and dominated the final frame.

Sean Couturier had a hat trick and set up Rasmus Ristolainen’s game-winning goal by skating the puck into the crease on a third-period 4-on-3 as the Wild lost their first game in regulation this season, 7-5, at Philadelphia’s Wells Fargo Center.

Marcus Foligno scored two of the Wild’s season-high five goals, but the Wild were outhustled and outmuscled at key times, especially in the third period, and the Flyers punished what had been the NHL’s stingiest defense.

Minnesota started the game leading the league in goals-against (1.86), first-period goals allowed (one) and allowing the first goal (zero times). They also had at least a point in their first seven games. But the worst team in the Eastern Conference — 1-5-1 at puck drop — taught the Wild a lesson about effort, starting the game on top of every Minnesota skater while taking a 2-0 lead in the first 3:51.

The Wild (5-1-2) tied the game 3-3 on Joel Eriksson Ek’s power-play goal with 3.2 seconds left in the second period, and Foligno tipped in a Zach Bogosian shot from the point to give Minnesota a 4-3 lead early in the third period. But the Flyers kept coming and the Wild buckled.

Filip Gustavsson, who started the day No. 1 in goals-against average (1.40) and second in save percentage (.952) had his first rough start, allowing three goals on the Flyers’ first six shots. Philadelphia had lost six straight (0-5-1) before Wednesday’s win.

Samuel Ersson wasn’t sharp in net for Philadelphia, giving up a goal on Jake Middleton’s floater from the right point that tied the game 5-5 with 6:32 remaining, but Ristolainen swiped home a pass from Couturier for a 6-5 lead with 2:24 remaining.

Ersson stopped 21 of 26 shots on net, Gustavsson 16 of 22.

The Wild pulled Gustavsson for a 5-on-4 advantage with under 2 minutes left in regulation, and Couturier found himself alone with the puck in the neutral zone and skated in for an easy empty-netter that sealed it with a minute left.

Brock Faber also scored his first goal of the season for the Wild, who next play Tuesday night in Pittsburgh in a 6 p.m. drop at PPG Paints Arena.

Briefly

The Wild were without forward Ryan Hartman (upper body) and defenseman Jared Spurgeon (lower body).