Ellis scored after 73 minutes and, although Tom Bird later hit a post for K’s, the Sussex side worked hard and deserved their victory.
They are still in a relegation place, a point above Carshalton – who return to the bottom – and a point behind Lewes, but with several games in hand on both.
An Emiel Aiken double dented Heybridge’s Ryman North play-off hopes as they were beaten 2-1 at Tilbury.
All the goals came in a three-minute burst shortly before half-time. Aiken rounded keeper Nicky Eyre to open the scoring (pictured by Elliot Mercer, with the stranded Eyre in orange) and followed up with a thumping header to make it 2-0.
Heybridge replied at once when Ben Newson found the net with an intended cross but their heavy second-half pressure brought no reward. They remain five points above sixth-placed Witham but have now played a game more.
There is a busy programme tomorrow (Tuesday), with 15 league games as well as the League Cup final between Dulwich and Concord at Maidstone.
Results will be posted as usual on this website as soon as possible after games finish but it will not be possible to provide the round-up of the night's games until mid-morning on Wednesday.
Keep up-to-date with our exclusive email newsletters.
Subscribe