The Magpies started the day sweating on their place in the division and facing a tough challenge against Brighton, but defeats for Dagenham and Walsall meant they were safe whatever the scoreline with Dagenham suffering relegation.
An entertaining first half saw the visitors go ahead on 11 minutes through a wonderful curling strike by the lively Ashley Barnes.
Chances for both sides followed but it was County who levelled on 36 minutes when dangerman Craig Westcarr's low cross-shot was deflected into the net by Brighton skipper Gordon Greer.
The second period started badly for the Seagulls as talismanic centre-half Tommy Elphick had to be stretchered off following an innocuous-looking collision.
Chances dried up but the noise was raised to pandemonium as Dagenham and Walsall continued to leak goals elsewhere and the home fans knew safety was an inevitability and the final whistle was greeted by a mass pitch invasion.