Joe Oates scored 'Side's winner, from the penalty-spot on 75 minutes.
The result, Alex Goldstone's first win in charge since being appointed Interim Manager, see's the Sky Blues advance to the quarters of the competition.
They will face Saffron Walden Town at home, with the winners of that tie going on to the semi-finals. A date for this match at Cricklefields will be announced in due course.
Updated 23:37 - 20 Dec 2018 by Adam Dennehey