An Amari Morgan-Smith hat-trick was enough to help the Reds survive a late scare from Curzon Ashton.
Alfreton seemed comfortable in the game having gone three goals ahead, but late controversy saw the visitors pull back two late goals.
Morgan-Smith opened the scoring after just eleven minutes. Danny Clarke put in a great ball for the forward who tapped it home at the near post.
Just nine minutes later the Reds had a penalty after Danny East was brought down in the box.
Morgan-Smith stepped up to take it and fired his effort against the underside of the crossbar with the ball just sneaking over the line.
The forward had a chance to complete his hat-trick just before the break after the Reds received another penalty.
Josh Wilde was brought down in the box this time, but Morgan-Smith couldn’t convert, with the Curzon Ashton goalkeeper guessing the right way.
But Morgan-Smith would claim the match ball in the second half, capitalising on a poor back pass from the Curzon Ashton defence and slotting the ball past the keeper.
The Reds looked comfortable in the tie, but with three minutes to go the Nash were given a lifeline.
Clarke was deemed to have handled the ball in the box, with the referee giving the forward a second yellow card.
Luke Wall converted what looked like a consolation goal with just minutes left in the tie.
But the visitors piled the pressure on in added time, Matthew Regan reduced the deficit with just minutes left.
However, the Reds held on to claim three points and rise to fourth the league. The Reds are still unbeaten at home so far this season.
Alfreton could have easily been five goals ahead heading into the final moments of the game, with Cameron Mason saving one-on-one against Nyle Blake and Josh Clackstone as well as his excellent penalty save.
The Reds can be happy with their performance, having blown Curzon Ashton out of the water for 80 minutes, but will be disappointed that they let their comfortable lead slip.
Morgan-Smith has now scored 10 goals in 10 games so far this year, sitting second top scorer in the National League North and proving to be one of the best players in the league this year.
Alfreton Town: Atkinson, Clackstone, Wilde (C), Lynch, Killock, Qualter, Thacker, Smith, Clarke, Morgan-Smith (Blake 77), East.
Unused Substitutes: Whitham, Williams, Hinchley.