Zubrus put New Jersey ahead 3-2 late in the second period and iced it with an empty-net goal in the final minute.
Petr Sykora and Marek Zidlicky also scored for the Devils, who can advance to their first conference final since 2003 with a win in Philadelphia on Tuesday night. New Jersey has never lost a playoff series after taking a 3-1 lead.
In winning their third straight, the Devils let goalie Martin Brodeur have an easy night on his 40th birthday, outshooting Philadelphia 43-22. He even picked up an assist on Zubrus' final goal.
Scott Hartnell and Claude Giroux scored first-period goals for the Flyers, who once again were a step slow.
The Flyers seemed to come apart at the end of the game. Defenseman Kimmo Tomonen took a foolish penalty in the closing minutes and Philadelphia never got off a good shot after pulling goalie Ilya Bryzgalov in the final minute.
In fact, Zubrus was about to score into an empty net when he was hooked. Still, the puck went off his stick and into the net.
That's how dominant the Devils were against a Flyers group that has fallen apart after knocking off the Pittsburgh Penguins.
New Jersey outshot Philadelphia 32-12 in the first two periods, but the shots advantage only translated into a 3-2 lead, with the Devils scoring three in a row to wipe out a 2-0 deficit.
Zubrus gave New Jersey its first lead with 2:13 left in the second period. The Flyers actually broke up a 3-on-1 break into their zone, but they lost sight of Zubrus, and Adam Henrique found him all alone in front for a shot that went in off Bryzgalov.
Moments before the goal, Brodeur stopped a shot from the point by Timonen, and Hartnell couldn't get off a good shot on the rebound with Brodeur down and the net open.
Sykora, who might have gotten a piece of Hartnell's rebound attempt, quickly led the 3-on-1 counterattack and the Devils pulled ahead.
The Devils forced Flyers coach Peter Laviolette to use his timeout less than 5 minutes after the opening faceoff, and for a couple of minutes it appeared to be a magical move.
Getting a lift from its special teams, Philadelphia jumped to a 2-0 lead.
Hartnell gave the Flyers the lead, deflecting Giroux's shot past Brodeur seconds after Travis Zajac was tripped and took a retaliatory interference penalty.
Giroux, who had been invisible in the Devils' wins in Games 2 and 3, doubled the margin at 13:40 by beating the birthday boy on a 2-on-1 short-handed tally after taking a great break-in-pass from Maxime Talbot.
The goal came 13 seconds after Philadelphia defenseman Andreas Lilja was called for tripping, but the Devils dind't let the man advantage go to waste.
Sykora cut the Devils' deficit in half late in the power play, redirecting a nice cross-ice pass by Zidlicky past Bryzgalov, who was a little slow covering the corner of the net after the defenseman made the pass from the right point to the left edge of the crease.
Zidlicky tied it with 1:51 left in the period after the Flyers' seemed to lose sight of the defenseman after he pinched down from the right point. The puck ended up on the left point and fellow defenseman Bryce Salvador found Zidlicky between the circles for a redirection.
NOTES: Devils fourth-line C Ryan Carter was scratched because of an illness. Tim Sestito played in his first NHL postseason game replacing him. ... Sean Couturier, who missed the final two periods of Game 3 with a lower-body injury, was back in the Flyers' lineup. ... Ilya Kovalchuk provided some entertainment in the third period attempting to keep a puck in the Flyers' zone with a header at the blue line. He failed. ...The Devils have sold out all five of their home games in the playoffs.