Dover dropped to fourth in the Blue Square Bet Conference South after losing 3-2 away to Hampton & Richmond Borough.
A dreadful first half display from The Whites saw the home side race into a three-nil lead inside the opening 40 minutes.
Ian Hodges opened the scoring with a free header from a second minute corner and the Beavers doubled their lead shortly after the half-hour mark when Charlie Moone bundled the ball in from close range. The striker made it a brace five minutes later, chipping Dover's Ross Flitney after a defensive error by Olly Schulz.
The visitors pulled one back just before the break. Matt Fish's powerful strike was well saved but Schulz headed home from the resultant corner to give Dover a lifeline.
The Whites dominated the second half but struggled to break down their opponents. A 91st minute penalty for a hand ball in the area was converted by Adam Birchall but it proved to be a mere consolation for Martin Hayes' side.