After 13 minutes of Saturday's replay, United trailed 3-0 and looked set to make a sorry cup exit.
After conceding a goal in the first minute, the visitors then conceded two goals in a minute to be left apparently without hope.
A goal from Andy Johnson after 16 minutes, after the home goalkeeper had failed to hold a strong shot from James Lock, appeared to offer little hope as Ramblers continued to dominate.
On the stroke of half time, Matt Ohene seized onto a knock down from John Morgan and volleyed the ball home.
Suddenly the game was transformed, and from the kick-off after the interval, Braintree pushed forward.
A corner from Johnson was flicked on by Morgan and Tim Hart headed home to equalise on 57 minutes.
Within a minute, Ohene was denied from close range as a constant stream of crosses from Gary Rolfe put the home defence under continual threat.
After 66 minutes, United completed an astonishing comeback as Lock swung over another cross, and Morgan rose to head the visitors into the lead.
Ramblers almost stole an equaliser when Darren Harding unleashed a drive of ferocity which had goal written over it until Ingram appeared from nowhere to turn the ball aside.
Another golden opportunity was spurned by Morgan but, despite some late Ramblers pressure, Ingram and his defenders made sure that United claimed a famous victory and a place in the semi-finals for the third successive year.
Converted for the new archive on 19 November 2001. Some images and formatting may have been lost in the conversion.
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