The Hibs are out of the Macron Scottish Junior Cup following a disappointing performance against Fauldhouse who had David O'Donnell to thank for two great strikes that earned the visitors the victory that takes them into the fourth round draw.
It was Thornton who created the first goal-scoring opportunity in the 2nd minute when Daniel McNab's strike from the edge of the box brought out a fine save from Matthew Craig.
O'Donnell opened the scoring in the 20th minute when his well-taken free-kick entered the net low down just inside the post. Craig made another fine save to deny Garry Thomson and followed this up with a brave save at the feet of McNab as Thornton tried to get back into the game.
On the stroke of half-time Fauldhouse had a great opportunity to double their lead when Scott Costello brought down Aiden Ward in the area however Costello atoned for this by saving Aaron Connolly's penalty-kick.
Three minutes into the second-half, Garry Thomson scored his tenth ever goal in the Scottish with a terrific free-kick to level affairs and not long after this, Andy Adam's free-kick was well saved by Craig with Thomson and Shaun Keatings watching in disbelief as their close in efforts were blocked on the line.
O'Donnell's brilliant strike from outside the area in the 83rd minute gave Costello no chance and in doing so it spoiled what was Craig Gilbert's 400th game in charge of the Hibs.
Thornton Hibs: Costello, Ford, Robertson, A.Drummond, Shields, Adam, Keatings, Orrock, B.Anthony, Garry Thomson, McNab. Subs: Ireland, Garry Thomson jnr, D.Anthony, Cooper, Warrender.
Fauldhouse United: Craig, Herriot, Daly, Watson, Brady, Henderson, O'Donnell, Ward, Connolly, Duffy, McCafferty. Subs: Macleod, Dunn, Johnston, Smillie, Wallace.
Referee: Mr J.Curran
Match statistics:
Attempts at goal - TH 14 FU 5
Attempts on target - TH 8 FU 4
Corners - TH 5 FU 5
Offside - TH 1 FU 6
Fouls committed - TH 18 FU 12
Yellow Cards - TH 7 FU 5
Red Cards - TH 1 FU 0