Danny Meadows's 89th-minute winner earned Alfreton all three points in a thrilling encounter against Dartford.
The Darts scored when Ryan Hayes netted from 15 yards, before Meadows headed in Nathan Arnold's cross to equalise just before the break.
However, the visitors were back in front through Nathan Collier's header.
But the Reds again came back when Anton Brown poked in from close range, before Meadows struck from inside the area late on for a memorable win.
VIEW FROM THE DRESSING ROOM
Dartford manager Tony Burman told BBC Radio Kent:
"To come away from home, score two goals and then lose is a bitter pill to swallow.
"I'm not saying we tore them apart, but we had three great chances, and one dubious offside goal. I'm really disappointed.
"We have got to add to our squad and get some fresh legs in. That's what I will keep trying to do."
Alfreton Town 01 Barnes 02 Law 03 Franklin (Harriott - 34' ) 10 Bradley (Worsfold - 65' ) 12 Franks 17 Streete Booked 23 Killock 07 Brown 14 Meadows 11 Arnold 21 Tomlinson Booked (Clayton - 53' ) Substitutes 05 Quinn 16 Harriott 19 Russell 09 Clayton 20 Worsfold Dartford 12 Bettinelli Booked 02 Rose Booked 04 Champion 13 Rogers (Eisa - 90' ) 16 Arber Booked 08 Wallis 10 Bradbrook (Monger - 90' ) 20 Burns 07 Hayes 09 Erskine (Collier - 16' ) 21 Crawford Substitutes 24 Sutton 30 Eisa 15 Collier 18 Martin 26 Monger
Ref: Anthony Backhouse