Having conceded two goals in a shambolic opening period of play, courageous Macclesfield went through the gears to stun Wrexham into submission.
The Welshmen took the lead in the eighth minute when Mark Jones produced a neat back-heel for Sam Williams to drill a low shot that was deflected past the stranded Tommy Lee.
Macclesfield then went close to equalising when Danny Whitaker shot over the bar from 25 yards before dragging a volley wide.
However, Wrexham extended their lead in the 32nd minute when centre-back Andy Holt met a Shaun Pejic cross with a stooping header from eight yards.
But Holt was to turn from hero to villain in the 48th minute when he bizarrely lost his bearings as he thumped a header past his own keeper and handed Macc a lifeline.
The Silkmen almost equalised in the 71st minute when Martin Bullock jinked his way into the box only to blast a drive over the bar from 15 yards.
The home fans did not have long to wait to celebrate another goal though as makeshift centre-forward David Morley nodded a long punt into the path of Whitaker who buried a volley from 15 yards.
Joy turned to delight seven minutes later when rapidly improving central defender Andrew Teague out-muscled his counterpart to head home an unexpected winner from four yards.