The win seemed to have been secured when Richard Salmon scored a third, but Hendon came roaring back and were rewarded when Jono Nesbitt's teasing cross was diverted in for the second own goal of the game.
Hendon continued to press and when Jaimie Grossman popped up at the back post to reduce the deficit to 3-2, a remarkable comeback looked on, but despite further pressure they could not force an equaliser.
Young told JC Sport: "I am delighted to progress to the semis and no-one cares how you get there, you just need to get there.
"We somehow let Hendon back in the game with two extremely soft goals and credit to them as the battled well throughout the game and the young Korman was impressive in the middle."
Hendon manager Adam Glekin told JC Sport: "I can't fault the effort of the boys, we could have folded at 3-0 down but we came back brilliantly and gave them a real scare.
"Both teams were without some key players, but it was a decent game. Congratulations to FC Team and we wish them luck in the semis.
"We've got two league games left now to finish the season off and I'll be making sure there is no slacking as I want six points."
