It was sheer ecstasy for caretaker manager Jim Leishman as he brought his beloved Pars back from the brink, although he would have been the first to admit that fortune favoured his team as they were outplayed in the second half as United missed a hatful of chances
In front of a large, vociferous away support, it was the Pars who created the first chance of the game in the eighth minute with a free-kick 25 yards out. Ian Campbell did well to curl it over the wall but Tony Bullock matched the shot with a fine save.
The ball was in the air more than on the ground in the opening half, an apparent tactic by Dunfermline. United appeared to be sucked into it and as a result, it was the visitors who dominated the early possession, without carrying any major threat.
Lee Makel did have a sight of goal in the 20th minute following a breakaway from a Barry Robson free-kick but his 20-yard swipe flew past the post.
The tension across the United team was visible for all to see with numerous unforced errors making it very frustrating for caretaker manager, Gordon Chisholm pounding his technical area. It took his troops 25 minutes before carving out their first chance, a glancing Jim McIntyre header over the bar.
But the pressure continued towards Bullock's goal. A neat move on the right just past the half hour caused panic in the home defence with Mark Kerr heading over his own bar, before Craig Wilson had a long-range effort which Bullock easily held on the stroke of half-time.
Ex-Par Stevie Crawford, who was almost anonymous throughout, opened the second half with a neat flick which narrowly went wide. But the ball swung to the other end where referee Stuart Dougal pulled up Derek Young for a foul before his brother Darren smacked the ball into the net, much to the fury of the black and white clad supporters.
But the Tangerines came close in the 56th minute when McIntyre hit the post. Following a goal line clearance from Campbell, the ball came back into the box but the striker could only hit the woodwork when he should have scored.
United were now completely dominant. A brilliant save from Derek Stillie prevented Robson from opening the scoring with a downward header. Then, Wilson threw himself down on the line to block Crawford's follow-up.
The keeper again produced a superb save in the 71st minute when he took two attempts to hold Robson's curling 20 yard free-kick. It was all hands on deck for the Pars as Scott Wilson blocked Crawford's shot three minutes later.
As United continued to dominate and create the chances, they were dealt a blow six minutes from time when Paul Ritchie was stretchered off to be replaced by David McCracken.
But then real disaster struck for the Tangerines when a cross deflected off Kerr and struck Gary Mason before bouncing into the goal to give the Pars the points.