Fleischmann took a pass from Weiss to the left of the net and shot it past Martin Brodeur for the game winner.
"Those guys didn't cover me and I was there by myself," Fleischmann said. "I felt you have to do something against Brodeur because he had a great angle, so I just faked the shot, went to the side and it worked out."
It was only the second time in franchise history the Panthers overcame a three-goal deficit. On Feb 10, 2009, the Panthers trailed 4-1 against Toronto before winning 5-4 in OT.
"We found a way to win," Versteeg said. "We're going to have to be happy about that tonight and just let the game go and come back on an even keel tomorrow."
Devils coach Peter DeBoer, who coached the Panthers for the last three seasons, returned to the Sunrise arena for the first time since being fired on April 10. He didn't get the revenge he had hoped for.
"It's disappointing. We stopped playing after the 3-0 lead," DeBoer said. "A good lesson learned and a credit to them, they didn't stop. We probably got what we deserved at the end."
New Jersey scored all of its goals in the first, and Florida tied it on Weiss' short-handed tally at 9:12 of the third. Garrison passed to Weiss in front and he wristed the puck high into the net.
After Weiss' goal, the Devils had a two-man advantage for 1:05 but couldn't score.
The Panthers got on the board on Versteeg's first goal at 5:28 of the second. Versteeg grabbed a loose puck in front of the crease and poked it past Brodeur on the stick side.
Versteeg scored again five minutes later. Jason Garrison's shot was blocked by Brodeur, but Versteeg was there for the rebound and wristed it into the net.
"It's disappointing because of the way you lose," Brodeur said. "In this league, three-goal leads, especially when you have a lot of time on the clock, it's never safe."
New Jersey's fast start was the first time the Panthers allowed three goals in a period this season.
The Devils took a 1-0 lead on Kovalchuk's goal at 8:17. Theodore blocked a shot by Henrik Tallinder but Kovalchuk got the rebound and wristed it into the net.
Sykora then backhanded in a shot on Theodore's stick side, and Zubrus' score at 11:49 made it 3-0. Patrik Elias passed across to Zubrus to the right of the crease and he swept in the puck.
The Panthers said there was no extra satisfaction from beating their former coach. They just want to win games.
"It's got nothing to do with him at all," Weiss said. "It was unacceptable the way we started that game. We had to push back, and we did. It's a big win for us."
New Jersey D Anton Volchenkov needed 12 stitches to the face after a first-period injury. ... New Jersey C Ryan Carter played his first game against his former team. Carter was waived by the Panthers on Oct. 25 and picked up by the Devils the next day. ... Versteeg has 11 goals in 20 games for the Panthers. ... Florida C Marcel Goc missed his third game with an upper body injury.
Copyright by STATS LLC and The Associated Press
Arena: BB&T Center Location: Sunrise, Florida
Referees: Paul Devorski, Tom Kowal Linesmen: Brian Murphy, Brian Mach
Attendance: 13,122 (68.2% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
Ilya Kovalchuk (4)
Assists: Henrik Tallinder, Andy Greene
Petr Sykora (4)
Assists: Adam Larsson, Andy Greene
Dainius Zubrus (6)
Assists: Patrik Elias, Martin Brodeur
Kris Versteeg (10)
Assists: Stephen Weiss, Dmitry Kulikov
Kris Versteeg (11)
Assist: Jason Garrison
Stephen Weiss (8)
(Shorthanded) Assists: Jason Garrison, Mike Weaver
Tomas Fleischmann (9)
Assists: Stephen Weiss, Kris Versteeg