In the latter stages of the second period, Grant Clitsome (slot shot), Kyle Wellwood (scoring on scramble in front), Evander Kane (scramble in front), and Bryan Little (left-circle blast) scored for the Jets to erase a 1-0 deficit.
Clitsome and Wellwood scored 27 seconds apart while defenseman Luke Schenn was being stitched in the locker room after taking a puck off his head.
The Flyers' defense was already missing Andrej Meszaros, Braydon Coburn, and Nick Grossmann because of injuries, and veteran Kimmo Timonen gamely played but skated gingerly after being injured in Thursday's 5-3 win in Toronto.
"We're pretty beat up," said goalie Ilya Bryzgalov, whose team hopes to get Grossmann back on Tuesday against the host New York Islanders. "Lots of guys playing lots of minutes. We spend a lot of emotions and energy."
After controlling the first period - outshooting the Jets, 13-4, and getting a tip-in goal from Ruslan Fedotenko to take a 1-0 lead - the second period was one of the Flyers' worst of the season. They allowed numerous odd-man rushes and continually failed to clear bodies from in front of the net as they were outscored, 4-0, and outshot, 12-5, in a stanza that turned into a Winnipeg shooting gallery.
"The last 40 minutes, they played like they were playing for a playoff spot and we were already down and out," winger Scott Hartnell said. "They took over the game. They were harder on pucks. They were physical. They had a few plays from behind the net. They had body position and outmuscled us in front."
"We sucked," winger Wayne Simmonds said. ". . . We reverted back to our old ways."
Bryzgalov, who surrendered four goals on 16 shots, was serenaded with mocking chants of "Il-yaaaaah" as he skated off the ice to end the second period. Steve Mason, acquired from Columbus on Thursday, replaced Bryzgalov at the start of the third period and stopped all nine shots in his Flyers debut.
"It just goes to show that the way we've had success lately is hard work for a full 60 minutes," Luke Schenn said. "If you take some shifts [off], or in that case the whole period off . . . we didn't compete, we weren't physical and didn't bring it that period, and we got it handed to us."
Contact Sam Carchidi at firstname.lastname@example.org. Follow on Twitter @BroadStBull.