A brilliant display from County goalkeeper Bartosz Bialkowski was also key for County as they climbed out of the relegation zone and heaped more misery on basement boys Stevenage.
The Magpies' goalkeeper was in outstanding form at Broadhall Way, denying Francois Zoko and Felipe Morais early on before saving his best for Lucas Akins, who he denied on several occasions.
With Stevenage frustrated by his heroics, Shaun Derry's side took the lead in the 42nd minute when substitute Ball drove the ball home through a crowded penalty area.
Stevenage attempted to launch a fight-back after the break, but it was the visitors who looked the more threatening.
Ball was denied a second goal by home keeper Chris Day, while Jon Ashton's brilliant tackle denied Andre Boucaud.
Stevenage boss Graham Westley went for broke late on, but his side could not unlock a defence marshalled superbly by Dean Leacock as County secured a third successive win.