"We knew this would be a tough environment, and not only were we well-prepared for it, they thrived on it," Rangers coach Alain Vigneault said after his team regained the home-ice advantage.
In franchise history, the Flyers are 7-20 in series in which they trail by 2-1.
"We're going to be ready for Game 4, we're going to tie up this series and go back to New York," Flyers captain Claude Giroux said.
The Rangers blocked 28 shots (Girardi blocked five of them) and frustrated the Flyers into an 0-for-5 performance on the power play.
"Everything has to happen quicker," defenseman Kimmo Timonen said. "We've got to get pucks through somehow, if it's moving the puck sideways or whatever. But I have to give [the Rangers] a lot of credit. They do a really good job - not just the 'D,' it's the forwards. Everybody.
"I'm sure we're going to watch tape and try to find a way to get pucks through and get some traffic there."
With his team trailing, 3-1, Scott Hartnell fired a shot that hit Lundqvist's stick and went off the left goalpost with 17 minutes, 8 seconds left.
It was the closest the Flyers would get to making it a one-goal game in the third period.
Eight minutes later, ex-Flyer Dan Carcillo, of all people, came out of the penalty box, took a pass from Brian Boyle, and beat Ray Emery to make it 4-1.
Steve Mason, getting a tune-up for a likely start Friday, relieved Emery and played the final 7:15.
Earlier, after a poor Flyers line change, Girardi scored on a point blast that went over Emery's shoulder on the short side, giving the Rangers a 3-1 lead with 14:43 left in the second period.
The Flyers had a 13-4 shots advantage in the second period but couldn't put the puck past Lundqvist, who had great support from his shot-blocking defense.
The Rangers blocked 20 shots in the first 40 minutes, including five on a labored Flyers power play late in the second period.
The Flyers' power play clicked at a league-best 25 percent on the road this season, but was successful just 15 percent of the time at home.
The Flyers had a 32-23 edge in shots, but it hardly mattered.
The first period had a siscript similar to that of Game 2, won by the Flyers, 4-2, Sunday in New York.
Just like that game, the Flyers fell into a 2-0 hole and got to within 2-1 on a late first-period goal.
On-charging defenseman Mark Streit scored from the slot, one-timing a perfect right-circle feed from Jake Voracek with 2:42 left in the opening period.
Giroux started the play when he knocked down defenseman Ryan McDonagh at center ice, causing a turnover and feeding Voracek on the right side.
Until Streit's goal, the Rangers were in command.
"We didn't have the start we wanted," Streit said.
Emery allowed a soft goal as he couldn't glove Rick Nash's left-wing shot and inadvertently handed the rebound to Derek Stepan for a tap-in after 3:54 of the first period.
Six-plus minutes later, the ageless St. Louis made it 2-0. After knocking down Timonen behind the net, St. Louis got position in front and tipped in Girardi's point drive.
It was the second goal of the series for St. Louis, who scored just once in 19 games after the Rangers acquired him from Tampa Bay late in the regular season.
The Flyers were outshot, 69-40, heading into Game 3.
They had enough shots to win Tuesday, but Lundqvist stood tall, as he usually does.