One night after losing to an Ottawa team that was last in the Atlantic Division, the Flyers built a 3-0 lead Saturday and appeared to be in control against one of the NHL’s powers.

But they collapsed in the third period and fell to the rested New York Islanders, 4-3, in a shootout at the Wells Fargo Center.

Jordan Eberle and Mathew Barzal scored in the shootout, while the Flyers failed to connect on shots by Sean Couturier, who hit the crossbar, and Claude Giroux.

Two bad line changes by defensemen late in the game -- one led to an Islanders goal, the other gave New York a power play, which it converted into a goal -- proved costly for the Flyers.

“It’s just focus. We’re old enough to recognize when you have to be on the ice or not," left winger Oskar Lindblom said. “It’s not good enough, and we have to be better.”

“It’s tough. We pretty much gave up two points to them,” said Couturier, who, like Lindblom and defenseman Ivan Provorov, had a goal and an assist. “We can’t afford to be giving up these two points.”

It was the Flyers’ third straight defeat, while the Islanders, against all odds, extended their point streak to 14 games.

Anthony Beauvillier scored on a bouncing shot that handcuffed Brian Elliott with 2 minutes, 4 seconds left in regulation, knotting the score at 3-3. It was his second goal in the third period.

The Islanders took advantage of a bad Flyers defensive change to get to within 3-1 with 12:14 left in regulation as Beauvillier got ahead of the pack and beat Elliott with a backhander.

With the Isles on a power play -- a bad defensive change gave the Flyers a too-many-men-on-the-ice penalty -- and less than eight minutes left, Matt Niskanen blocked a shot as Elliott scrambled out of the net, and Prorovov then played goalie and denied Anders Lee from in close.

But the Islanders cut it to 3-2 with 6:26 left on Barzal’s power-play goal from the doorstep. The Flyers, playing on back-to-back nights, looked fatigued.

“It’s a tired bunch of guys after a game [Friday] and getting in late,” Elliott said. “I think it caught up with us with a couple decisions here and there and [defensive] changes. It just kind of all added up. We tried to weather the storm. We got a point out of it, but it’s definitely frustrating.”

The Flyers took control early, getting first-period goals from Couturier and Provorov (power play ) to take a 2-0 lead. Operating against the league’s stingiest defensive team, the Flyers had the last 11 shots in the period.

Couturier took a slick pass from Lindblom and scored from the high slot just 1:38 into the game, matching the Flyers’ output in their lackluster 2-1 loss Friday in Ottawa.

“He has the ability to make those good passes, and it was a sick play," Couturier said.

After Couturier’s goal, the Islanders controlled play for several minutes before the Flyers regrouped.

“We got a big goal early, but they came out strong and were all over us,” Couturier said.

Elliott, however, had all the first-period answers and the Flyers started winning puck battles and dominated the rest of the period.

With 24 seconds left in the first, Couturier set up Provovov for a one-time point drive that got past Thomas Greiss, who appeared to be screened by Lindblom. The Flyers had been on a 2-for-21 power-play rut before Provorov connected.

The Isles dominated the second period and outshot the Flyers, 13-4, but Elliott was both good and fortunate as Casey Cizikas hit iron for the second time in the game. Elliott stopped all 13 shots he faced in the second, including a point-blank attempt by Beauvillier. He also made a diving save on Barzal during an Isles power play.

Lindblom, on one of the few Flyers’ scoring chances in the second, scored from the left circle with 7:40 left in the period. It was his ninth goal in 20 games. Last season, he didn’t score his ninth goal until the 58th game.

Coach Alain Vigneault scrambled all four lines Saturday, and the Couturier unit, with Lindblom and Joel Farabee, was the most effective.

The other lines: Giroux centering Michael Raffl and Travis Konecny; Kevin Hayes centering James van Riemsdyk and Jake Voracek; and Andy Andreoff centering Chris Stewart and Tyler Pitlick.

Defenseman Phil Myers and winger Carsen Twarynski were scratched and replaced by Robert Hagg and Stewart, respectively.