With their playoff series tied, Saturday night’s matchup was a vital “swing” game between the Flyers and New York Islanders.

The pendulum swung to the Islanders.

Goalie Semyon Varlamov, rebounding from a poor performance, made 26 saves as the sixth-seeded Islanders defeated the top-seeded Flyers, 3-1, at Toronto’s Scotiabank Arena and took a 2-1 series lead in the Eastern Conference semifinals.

Game 4 is Sunday night at 8.

In NHL history, teams that break a 1-1 playoff tie and take Game 3 have won 67.1% of the best-of-seven series.

The Flyers are just 7-22 all-time when they trail a series, 2-1.

After Robert Hagg was called for slashing, the Islanders capitalized on the game’s first penalty and took a 3-1 lead on Anders Lee’s power-play goal with 16 minutes, 19 seconds left. Lee, with position on defenseman Justin Braun, put a backhander off Carter Hart’s stick for his third goal of the series.

Hart had been anticipating a pass to Mathew Barzal.

“We need to be a lot better than we were tonight, especially our top-end guys,” coach Alain Vigneault said. “The great thing about it is we can get right back at it (Sunday).”

Claude Giroux (three shots), Travis Konecny (three shots) and James van Riemsdyk (two shots) had chances but remained goal-less in the post season. Giroux has one goal over his last 25 playoff games.

“Our line can do better; we know that,” said Giroux, who was on a unit with Sean Couturier and Jake Voracek. “We generated some offense, but at the end of the day, it’s got to go in the net.”

Midway through the third period, Varlamov maintained the 3-1 lead with his best save of the night as he stopped rookie Joel Farabee from the doorstep. Varlamov had been pulled from Game 2 after allowing three first-period goals.

“I learned from mistakes and moved on,” Varlamov said.

After Tyler Pitlick’s goal with 5:42 left in the first, the Islanders started to tilt the ice and suddenly had an extra gear compared to the Flyers.

In a stretch than spanned until the middle stages of the second period, the Isles outshot the Flyers, 14-1, after Pitlick’s goal and scored the equalizer when Matt Martin converted Barzal’s pass and squirted a point-blank shot off Hart and into the net. Martin got behind defenseman Travis Sanheim and was alone in front with 12:48 left in the second.

“We were playing the type of game we wanted to play, and somehow we just lost it,” Vigneault said. “We stopped being first on pucks. Our players stopped making the plays we needed to make with the puck, and they slowly but surely found the momentum.”

An Ivan Provorov turnover led to Leo Komarov’s goal with 5.1 seconds left in the second, putting the Islanders ahead, 2-1.

“I put my top players on the ice, top line, top D pair,” Vigneault said of the waning seconds of the second period, “and to give up that late goal, you just can’t do that at this time of the year.”

The Flyers, who haven’t scored in the second or third periods in this series, were in retreat mode for most of the second period, during which they were outshot, 15-6.

“Our pace was completely different in the second,” Flyers center Scott Laughton said. “We didn’t make them turn as much as we should have and it showed.”

Laughton, arguably the Flyers’ best forward in the round-robin tournament, struggled with turnovers in the playoffs and was a healthy scratch Wednesday in Game 2, but he returned to the lineup Saturday and made an immediate impact.

Used mostly as a left winger in the regular season and playoffs, Laughton was shifted to center and he set up the first goal, Pitlick’s drive from just above the left circle late in the first. Van Riemsdyk and Provorov set a double screen in front of Varlamov

The Flyers, who were coming off Wednesday’s 4-3 overtime win, entered the night 8-0 in the postseason when they scored first and 0-3 when they didn’t.

Laughton’s line, with van Riemsdyk -- who has been a healthy scratch in four postseason games -- and Pitlick (four blocked shots) had the Flyers’ most attack time in the first two periods. (Laughton replaced his close friend, Michael Raffl, in the lineup.)

The Flyers have scored just one goal, total, in their two losses in this series.

“Guys are frustrated,” Giroux said. “I think we need to take that frustration and bring it as energy.”

They better do it quickly.

BLM video

A Black Lives Matter video was shown in the arena before the game, and players from both sides tapped their sticks in support. During the video, van Riemsdyk said, in part, that all NHL players “stand in solidarity for the Black players in our league.”

At the players’ urging, the NHL postponed two games Thursday and two Friday to protest racial injustice after a Wisconsin police officer shot Jacob Blake, a Black man, seven times.

Breakaways

The Flyers are 11-0 in games after a loss since Jan. 7. ... Varlamov and Hart are expected to again start on Sunday. Hart said he would be ready if called upon, but that it wasn’t his decision. “If not, I know Moose is more than capable,” he said, referring to Brian Elliott by his nickname. “He’s had a lot of playoff experience. He’s been great for us this season. ... Vigneault on the defensive-minded Islanders. “That’s a veteran team that knows how to play and plays a gritty, greasy game. ... I said this was going to be a greasy series. That means you’ve got to get involved. You’ve got to want to go to the tough areas. We’ve been good at bouncing back. I’m confident that’s what we’re going to do.” ... Nic Aube-Kubel had a game-high six hits. ... In the series, the Flyers are 0 for 4 on the power play, while the Isles are 2 for 6.