Dover booked their place in the Blue Square South play-offs with victory over Weymouth at Crabble on Saturday.
The win keeps Whites in second place with two matches remaining, although Chelmsford could yet pip them for the runners-up spot, if they win their final three games.
It was an eighth successive win for Andy Hessenthaler's side.
With Barnet defender Dan Leach recalled to his parent club and Matt Fish ruled out through injury, Dover had to make changes following the Easter Monday win at Welling.
Andy Hessenthaler’s side were in front after eight minutes when the Weymouth defence failed to deal with Nicky Southall’s free-kick and the ball ended up in the net.
Whites thought they had won a penalty early in the second half when a Weymouth defender picked the ball up believing referee Paul Kelly had blown his whistle due to an injury. Mr Kelly spoke to his assistant and instead gave a drop ball.
Dover hit the woodwork three times before Sammy Moore’s flying header from a Southall cross wrapped the game up.