Hart, who was only making his third senior start, was on hand to rifle the ball through a body of players into the top corner after a corner was partially cleared to him and complete a remarkable comeback after United had been 3-0 down inside 30 minutes.
To say it was a bad start to the fixture for United would be an understatement as goals from Lucas Pattenden and Alex Laing saw the visitors two goals up inside the opening ten minutes.
A third follwed as Mark Zydonik was allowed too much space from a corner and he headed into the top corner with under half an hour played.
Despite the scoreline, United stuck to their principles in the hope of getting back into the game.
The comeback started ten minutes into the second half as Sam Davison struck his first goal for the club.
United continued to press forward and with eleven minutes left, substitute Callum Hart (pictured) turned in the area and squeezed the ball into the bottom corner to make it 3-2 and setup an exciting final ten minutes.
And in the fifth minute of stoppage time, the comeback was complete as Sam Hart struck and secured a point for a youthful United side, who received rapptourous applause from the home fans as they left the pitch