Dover Athletic overcame Kent rivals Ebbsfleet United to win promotion via the Conference South play-off final.
Nathan Elder's second-half goal was good enough to see the Whites return to the top flight of non-league football for the first time since 2001-02.
A crowd of almost 4,300 packed into Fleet's Stonebridge Road as the sides vied for a place in Conference Premier.
Steve Brown's Fleet had been aiming for an immediate return to the top tier following relegation last season.
Brown, who was on the coaching staff at Dover last season, signed several players from his former club last summer after Ebbsfleet were taken over by a Kuwaiti-based consortium.
Dover, managed by Chris Kinnear, overcame Sutton United in the play-off semi-final and then beat an Ebbsfleet side who were on a 10-game unbeaten run at home.
The Crabble outfit will join Conference South title winners Eastleigh in the top flight next season.