Hunt headed past helpless goalkeeper Paul Jones from eight yards following a corner from Jamie McAllister to stretch Crawley's winless run to five games.
The hosts had dominated for lengthy spells - twice being denied by the woodwork as well as having two efforts cleared off the goal-line.
The Red Devils threatened again on the hour when a rasping drive from Adams was parried by Marek Stech, and a low shot from Mark Connolly was later cleared off the line by Dan Burn.
Crawley winger Nicky Adams should have put his side ahead late on but blazed wide before skipper Gary Alexander headed against the bar.
That left Hunt, on shortly before half-time for the injured Kyle McFadzean, to reluctantly take centre stage and provide the late drama.