DONEGAL Celtic stunned Crusaders tonight at Seaview to record what, for long periods, appeared to be a hugely unlikely victory in front of the Sky Sports cameras.
The Crues started in dominant form, striking the post through Michael Halliday after just nine minutes while David McMaster's follow-up was smothered.
Halliday went one better four minutes later with a close range touch after Stephen McBride had crossed from a David Rainey flick.
They almost doubled their lead on 21 minutes after Chris Morrow tested DC 'keeper Robert Robinson with a 25-yard drive.
Indeed, Robinson kept the visitors in the game with a series of outstanding stops throughout the first half.
He got down well to deny Gareth McKeown, kept out another Morrow long range effort and then pushed away a 20-yard McBride curler.
He was beaten, however, towards the end of the half only for the woodwork to thwart Halliday for the second time.
The opening exchanges of the second half were simply a continuation of what had gone before with Colin Coates having a free-kick from almost on the halfway line tipped over by Robinson while, moments later, he instinctively kept out a much closer Rainey attempt.
But despite this plethora of chances the Crues still held only a narrow lead - and this was wiped out on 66 minutes when Celtic captain Stephen McAlorum drilled a low 30-yard left-foot drive past Sean O'Neill.
And, remarkably, the visitors grabbed the winner with four minutes remaining.
A Johnny Harkness ball into the area was only cleared as far as McAllister who returned it back into the danger zone for the poorly marked Paul McVeigh to turn home.
Crusaders: O'Neill, McKeown, Leeman, Coates, McBride, McMaster, Morrow, Watson, Dallas, Rainey, Halliday subs McCann (not used), Gargan (not used), Owens (replaced McMaster 68), West (not used), Snoddy (replaced Morrow 87)
Donegal Celtic: Robinson, L. Bradley, P. Bradley, O'Hara, Harkness, McAllister, McAlorum, Henderson, Lambe, P. McVeigh, D. Murray subs Gowdy (replaced Lambe 61), Devine (not used), M. Burns (replaced Murray 87), Atkinson (not used), Glenholmes (not used)