IT WAS a plan that worked, though perhaps not exactly in the way City boss Steve Tully had envisaged.
Pre-match, Tully had explained his reasons for leaving Isaac Vassell on the bench, with top scorer Craig Duff instead partnering Matt Wright up front.
He wanted to use the pacy former Plymouth Argyle striker as a late impact sub and his plan paid off handsomely as Vassell rose to head home a Shane White cross five minutes from time, to take City into Monday's promotion play-off final against St Neots Town at Treyew Road (3pm).
Victory against the Cambridgeshire side, who won their semi-final 1-0 at Poole Town, will see City play in National League South (formerly Conference South) next season.
Tully said: "Vass wants to start, but he came on and did it against Corby and I thought he could do the same tonight, though I did not think it would be with his head."
Few would argue that the victory was not fully deserved, as City controlled the game for long periods, without being able to find the net.
But all that changed as extra time and penalties loomed when Shane White hooked in a cross from the right and Vassell rose to head past outstanding Hungerford keeper Paul Strudley for the winner.
The West Berkshire visitors, who were on the back foot for most of the night, never threatened an equaliser, leaving City and their fans to celebrate a famous night in the club's history.
From 17th last season and the well reported financial troubles before that, City have come a long way under the guidance of Tully, with the backing of club chairman Pete Masters and vice-chairman Pep Perryman, who rescued the club from the depths of despair.
And Masters could not keep the smile off his face at the end of the game. "We are just 90 minutes from promotion, just think of that," he said.
Since Tully took over towards the end of last season, he and assistant Wayne Carlisle have transformed the team's fortunes, taking them to a third place finish in the Evo-Stik Southern premier division and into the play-offs.
But Tully is realistic and experienced enough to know that the job is not yet done.
He said: "We will enjoy tonight, but then start working hard for Monday which will be another difficult game. This was just the semi-final, there's a final now to win."
City will go into the game confident of winning as they extended their unbeaten home record to 15 games, but St Neots, who finished fifth in the league, have lost just one of their last 20 matches since David Batch took over as manager.
After resting his first choice team for Saturday's trip to Histon (debutant Jack Crago got their goal), Tully named a completely new starting XI from the one that lost that game 3-1.
It was a decision that paid off, as after a typically frantic start it was a fresh-looking City who were largely in charge.
Craig Duff and Matt Wright both went close and Duff also headed against the post, when he should have found the net, but the offside flag spared his blushes.
For Hungerford, James Clark missed their best opening, as he blasted wastefully over, but that was the closest they came against a mean City defence in which Ed Palmer was outstanding.
It was a similar story after the break, with City continuing to press in search of a breakthrough and only the brilliance of Paul Strudley in the Hungerford goal kept the score 0-0.
He turned a piledriver of a free-kick from Ed Palmer onto the bar and Wright could not capitalise on the loose ball and the Hungerford keeper was at it again to keep out another Palmer free-kick.
It looked as if might be one of those nights for the home side, but their patience finally paid off with Vassell's priceless winner. Now they have just one more step to take and will be hoping for a four figure crowd to see them complete a remarkable comeback from the brink of extinction.