Chris Kreider had a goal and an assist, and Mika Zibanejad had two assists for New York, the No. 1 seed from the Metropolitan Division. Igor Shesterkin made 34 saves.
"Tight game, pretty much a one-goal game difference throughout," Rangers captain Jacob Trouba said. "We had some good looks and some rebounds. We got to find a way to get a couple more past [Bobrovsky]."
Lundell gave the Panthers a 2-1 lead at 10:22 of the third with a wrist shot from the left circle to beat Shesterkin, who was screened by Vladimir Tarasenko.
"That was huge," Lundell said. "We had some good chances in the third and we were playing pretty good. ... I felt like we just had chance after chance and we just kept grinding and trusted that we're going to get the chance and the goal, and we got it. We really just tried to stay on top of them and keep the lead."
Bennett scored an empty-net goal to extend it to 3-1 with 1:52 remaining for Florida, which has outscored New York 6-2 in the third period in the series.
"I think we have great composure," Bennett said. "Our starts haven't been great, haven't been what we wanted, but it just seems like as the game goes on, we are getting better and better."
Lafreniere made it 3-2 with 50 seconds left for the Rangers, who were 0-for-3 on the power play.
"Close isn't cutting it," Rangers defenseman Adam Fox said. "We got to capitalize on those chances in big spots. We have some looks but you don't win games based on getting looks, you got to capitalize."
Kreider gave New York a 1-0 lead at 2:04 of the second period with a short-handed goal. He broke up a pass attempt from Matthew Tkachuk in the defensive zone before skating in and scoring on a breakaway, wrapping the puck past Bobrovsky's left pad.
"He's fast, he gets going and just put the puck in his hands and let him do what he does," said Zibanejad, who had the primary assist.