Jagr had two goals and an assist, and the Rangers chased goalie Martin Biron and beat the Flyers 6-4 on Saturday night.
"We had to win this game to stay in the hunt for the playoffs," Jagr said. "We play probably the most important game of the season (Sunday against Toronto).
"When you have a three-goal lead, you're already thinking, 'Let's play smart and save some energy.' It doesn't work that way. You get them back in the game."
Thomas Pock, Martin Straka and Petr Prucha, each had a goal and an assist, and Ryan Callahan also scored for the Rangers, who won for the sixth time in seven games and held on to seventh place in the Eastern Conference.
The Rangers led 5-2 and 6-3 but had to hold on.
"I was, honestly I was," Jagr said about struggling to keep his focus. "You don't want to fly up and down, maybe (Sunday) you're going to miss it.
"It would be a different story if the game would be tied but we had the lead. We didn't play good enough."
Ben Eager had two goals, and Braydon Coburn and Ryan Potulny added one each for the Flyers, who have dropped two straight and six of seven. Nathan Guenin had two assists for his first NHL points.
Biron, 5-7-1 since being acquired from Buffalo on Feb. 27, was replaced by Antero Niittymaki at 7:15 of the second period after he allowed goals to Jagr and Straka within a minute to give the Rangers a 5-2 lead.
"It's tough to get a guy like Jagr, who's pretty big, off the puck," Biron said. "Their guys were doing a good job of cycling.
"They showed some great patience and that created a lot of situations where they didn't have to make that 45-foot pass."
Biron stopped only 17-of-22 shots. Henrik Lundqvist had 33 saves for the Rangers.
Rangers coach Tom Renney said it was good to see the his team create offence. New York had a five-game winning streak snapped Tuesday at Montreal.
"At this time of the year, it's not so much what you take, it's what you leave," Renney said. "And I thought we left Philadelphia a little too much.
"Had we not had six (goals), obviously this could have been a different outcome. Philadelphia played hard and took advantage of our turnovers and our unwillingness to engage. They certainly made a game of it and we have to be better than that (Sunday)."
Jagr scored his second of the game when he snapped a wrist shot over Biron's blocker. Straka scored from the left side after taking a cross-ice pass from defenceman Marek Malik.
After Coburn picked up a loose puck and scored, Prucha made it 6-3 on a power play with 50 seconds left in the second period. Potulny scored on a deflection at 1:59 of the third.
"The Rangers are an opportunistic team that capitalizes on their opportunities when they get them," Flyers coach John Stevens said. "We had some good flurries early and then we didn't and they did."
Pock and Jagr each had a goal and an assist in the first period as the Rangers took a 3-1 lead.
Pock put the Rangers ahead at 3:32 when he scored on a wrist shot from the top of the left circle.
Eager tied it 24 seconds later when he picked up a loose puck near the right boards, skated in and shovelled in his own rebound.
New York regained control at 5:52 when Callahan scored on a rebound.
The Rangers increased their lead to 3-1 at 11:59 when Jagr skated into the slot. He appeared to momentarily lose control of the puck, but reached out and slid it past Biron, who allowed three goals on only eight shots.
Eager brought the Flyers to within 3-2 at 4:00 of the second period when his shot from the left side bounced off the stick of New York's Ryan Hollweg.
"It happens," Lundqvist said. "I'm kind of used to it now. It's happened a lot this year. We kept battling even though they got some weird goals, rebounds, and deflections."
Notes: The Rangers won the season series 6-2 . . . D Pock has six points (three goals, three assists) in the last seven games . . . Biron denied LW Brad Isbister's short-handed breakaway attempt midway through the first period . . . Niittymaki played in his 100th NHL game . . . RW Jagr, C Straka, and LW Brendan Shanahan each have a team-high 28 goals for the Rangers . . . Flyers D Derian Hatcher sustained a hip flexor injury in the first period that got worse. He sat out the third period.