The Ducks took the lead in the 10th minute when, after efforts by Alan Coe and Vince Melisi had been blocked, Derek Duggan pounced to score a scrappy goal.
Davy Jones, Melisi and Coe all went close to extending United's lead but just when it looked like the visitors would reach half time ahead, Folkestone equalised when Gilbert beat his man before firing past United's debutant 16-year old goalkeeper Tony Cobb.
It took until the 85th minute for another goal when Folkestone appeared to have won the match when Markham chased a long clearance and in attempting to pass the ball back to Cobb was blatantly pushed from behind. Play was allowed to continue and White shot past Cobb.
Deep into stoppage time, with United looking set to leave Kent pointless, Kevin Tilley swung over a free-kick from the right side and Coe lobbed the keeper to earn his side a deserved point.
David Figg