Former Blues skipper Tom Naylor settled matters with a first-half header which deservedly gave Paul Cook’s impressive non-leaguers victory.
It was a season’s worst display from John Mousinho’s men, particularly in the first half, and here are our Pompey player ratings...
9. Terry Devlin - 4
(Replaced by 60 Kusini Yengi on 60 mins) No heroics this time from the teenager, who struggled to get into the match. Nonetheless, plenty of effort and endeavour from the youngster, even if a quiet match. Photo: Jason Brown
10. Paddy Lane - 5
Had a bright first half but quickly faded after the break, unable to make things happen. Was eventually swopped to the left wing with Kamara moving to the right, only to produce some dreadful crosses when Pompey needed him most. So disappointing. Photo: Jason Brown
11. Colby Bishop - 5
Barely involved, although not helped by appalling service. Regardless, little came off, with errant flicks and lay-offs and too easily handled by the Chesterfield defence. A rare, rare off-day. Photo: Jason Brown
12. Tino Anjorin - 4
(Replaced by Gavin Whyte on 44 mins) There had been a few surges through the heart of the Chesterfield defence and one lovely ball to the far post which was met with a Bishop header. However, worryingly, he went down after closing a man down outside the box, with a hamstring issue. It ended his game immediately and was substituted . Photo: Jason Brown