Kenny was not meant to be involved in team affairs, but rushed into the changing room to provide the words of wisdom that drove his side to an unlikely victory.
The Pars had been under the cosh in the first half and only sterling defensive work from Greg Shields and Scott Wlson kept Dundee United at bay.
Shields made a fine interception from Barry Robson's cross and then denied a certain goal when he threw himself in the way of Mark Kerr's 20-yarder.
United continued to dominate and Noel Hunt passed up another glorious opportunity before his side took the lead on 51 minutes.
Craig Conway was the architect and his cross was met perfectly by Robson to head home from eight yards.
It looked like United would coast to victory, but Dunfermline changed their shape with the introduction of Scott Muirhead and Freddy Daquin.
Shields got the last touch on Muirhead's corner to prod the Pars level on 75 minutes and then they grabbed all three points a minute from time.
Stevie Crawford hooked the ball in from the right which Daquin backheeled into Gary Mason's path and he applied the finishing touch from ten yards.