Zak Rudden's 25-yard stunner gave Falkirk three rare points as the Bairns battled to victory in Fife.
Dunfermline's miserable home record continued thanks to the quick-thinking of the on-loan Rangers striker, and some great goalkeeping from ex-Celtic stopper Leo Fasan.
The Pars were wasteful in front of goal too but Falkirk's battling qualities were finally rewarded with a win. They could have had more too had Paul Paton's effort been a few inches lower and hit the net, rather than the crossbar just after the break.
HOW IT HAPPENED: Dunfermline v Falkirk LIVE!
Rudden had the perfect response to a denied penalty claim in the 70th minute when he drove a wonderful dipping strike past Lee Robinson as Falkirk swung the balance of the game in their favour in a fiery derby day encounter.
From long before kick-off it was a cauldron of noise at East End Park. Requests for the noisiest band of Bairns fans to vacate their section fell on deaf ears - or perhaps weren't heard as they roared the visitors through the warm-up, only falling silent for the well-observed minute of silence pre-match.
It was just as animated on the park in a fiery first half, and the Pars burst into life, testing Leo Fasan within a minute of Andrew Irving kicking things off for Falkirk.
Kallum Higginbotham fired a low drive that the Italian parried, but only into the path of Andy Ryan. The Pars striker scored against Falkirk earlier this season and stroked a low effort straight at the prone goalkeeper.
The Pars really threw everything at the Bairns early on, but Ray McKinnon's re-inforced side held firm, and eventually fought their way into contention. And fight they did.
It was a scrap. Andrew Dallas handed early booking to Myles Hippolyte for kicking the ball away and then Prince Buaben for an off the ball incident, but he could have brandished many more with some ferocious takcles flying in. Instead he punished the petulance as Kallum Higginbotham was later penalised for a tug on Tommy Robson and Daniel Devine also went into the book.
The left-back was marked out of the game and forced Falkirk to play down the right. One intricate passing play advanced the Bairns but when Lewis Kidd crossed, only Zak Rudden was in the box.
Lack of a striker was almost irrelevant in the opening minutes of the second half as Paul Paton thumped a glorious effort onto Lee Robinson's crossbar and Falkirk had a chance to nick something from a game where they were perhaps second best but not out of it by any means.
From that early second half scare though the Pars began to pepper Fasan's goal with shots. Lewis Kidd scrambled one threat away, then Higginbotham stung the palms of Fasan. Substitute El Bakhtaoui should have done better with a chance ten minutes into the second period too.
After 71 minutes the Bairns really should have been ahead. Tommy Robson got down the left wing and whipped in a cross, just like his terrace song says he does. Lee Robinson, the Dunfermlien goalkeeper spilled the delivery and it fell for Paul Paton. He scrambled the ball back to Andy Iriving but the young midfielder blazed over with Robinson poorly positioned.
It was end to end stuff and the play was now in even balance, with Falkirk raising the tempo and effort levels. And it paid off.
Just moments before Rudden's thunderous opener, Deimantas Petravicius turned Ryan Williamson this way then that and skipped into the box only to be felled with contact from the defender. Andrew Dallas played on and moments later the Bairns were ahead with a wonderful strike from their on-loan Rangers striker.
Really there was nothing on fro Rudden, who'd dropped deep to muck in, and he showed his predatory awareness to catch Robinson out from 25yards.
The home fans were angry, and turned irate when Allan Johnston removed their two most dynamic and dominant forwards, Myles Hippolyte and Kallum Higginbotham in a double subnstitution.
It certainly felt like surrender from the Dunfermline boss, under pressure with a woefuil home record of just four points this season, and it remained with a defeat to the basement club in the SPFL Championship.