Cara Newton put the unbeaten East Midlands League leaders ahead on 28 minutes in front of nearly 200 at Belper Town FC but Melissa Johnson levelled just before the break.
Two goals in a five-minute spell then put the Rams in charge, Amber Denny’s 57th-minute effort added to by Jade Eaglefield.
Johnson then made it 4-1 to Derby County on 68 minutes with her second goal of the game and Jessica Howard completed the scoring in added time.
Although Long Eaton felt hard done by with the measure of defeat, they found there was great cause for celebration.
Bedworth United’s 1-0 loss at Rise Park meant they were crowned league champions and promoted to the FA Premier League for the first time in their history.
