Already trailing 2-1 after the first leg, the home side were hit by a further hammer-blow in the 28th minute when the referee awarded Darlington what was at best a highly debatable penalty which was converted by mid fielder Clark Keltie.
The home side drew level on the day just before the break with more than a little help from Darlington goalkeeper David Stockdale.
He failed to hold Adam Rundle's free-kick and the ball was forced over the line by a combination of home striker Chris Dagnall and visiting midfielder Ricky Ravenhill.
Just after the break Ravenhill was unlucky to see his effort from the edge of the box strike the crossbar but with 12 minutes left Dale took the lead on the day and drew level on aggregate when midfielder David Perkins riffled home an unstoppable 25-yard effort.
When the game moved into extra-time, Perkins was red carded following an innocuous challenge on Rob Purdie.
Unless his club can successfully appeal against what was at best a debatable decision, Perkins will now face the heartbreak of missing the play-off final on Bank Holiday Monday.
The penalty shoot-out saw four immaculate efforts from each side but, on the ninth, Quakers midfielder Jason Kennedy saw his effort saved by Dale keeper Tommy Lee.
That allowed substitute Ben Muirhead to become the hero as his effort found the roof of the net to send Spotland into scenes of celebration the like of which have not been seen since their last promotion party way back in 1969.