Chesterfield went out of the FA Youth Cup on Wednesday evening after losing 1-0 at Boston United, despite being on top for spells during the match.
The young Spireites made a bright start without testing keeper Charlie Wilkinson in the opening stages.
There was the threat of an opening when a low cross from Jacob Barrass just evaded Lekan Torres.
Midway through the half, Nathan Moss chipped just over from around 20 yards out.
Brad Charlesworth put a shot on target from just inside the area which was comfortably saved by Wilkinson.
As the Spireites continued to press, Moss saw his shot deflected wide.
Moss threatened again, hitting the side netting after getting on the end of a Barrass cross.
At the other end, a long-range effort from Joe Melson went well over and Sam Harris had a shot charged down.
In the closing stages of the half, the ball was hacked clear following Zane Millar’s low cross.
Francis Finnernan had a chance for Chesterfield on the break but, under pressure from a couple of defenders, he shot wide.
Chapman made a comfortable save from Han Stevens’ shot from the left-hand side of the area.
Charlesworth put a shot on target soon after the re-start which was kept out by Wilkinson.
Torres then saw his low cross/shot just evade Torres.
Out of the blue, the hosts took the lead when Foster (52) scored with a left-footed shot from the edge of the area.
A mix-up at the back saw Boston presented with an opportunity to extend their lead with Chapman making a good save to keep out a shot from Stevens and Dan Grierson blocking the follow-up.
As the Spireites looked to score an equaliser, Barrass played the ball to Moss whose shot went narrowly wide of the target.
Substitute Luke Mitchell, on as a replacement for Jack Allerton, played a one-two with Torres before firing a fraction wide.
Spireites: Chapman, Barrass, White, Grierson, Allerton (Mitchell), Wilkinson, Charlesworth (Waite), Hooper (Duhameau), Finneran, Moss, Torres