Forest have lifted the League Cup four times, but bowed out at the first round stage as Brian Horton's side claimed their first win of the season.
It was no more than they had deserved either as Forest - who had lost three consecutive matches in League One - took another dent to their confidence.
Macclesfield almost snatched the lead in the first minute with only a brave save from Rune Pedersen denying Kevin Townson as he eluded the Forest defence.
But Forest were soon on top and got their reward in the ninth minute after some fine work from Kris Commons.
The Reds midfielder almost forced an own goal from David Morley with a teasing cross, but from the resulting corner another accurate delivery from Commons picked out Ian Breckin who nodded home from close range.
Macclesfield did not look like a side that were yet to notch-up their first win of the season but they confidently hit back and got their reward within 10 minutes.
A clever move from a corner saw the ball worked to Danny Whitaker on the edge of the box from where he threaded a shot into the bottom corner of the net.
Whitaker could also have added a second before half time as he found space down the right and lofted an ambitious shot from 20 yards that had Pedersen scrambling back to save under his crossbar.
Forest's response was swift, however, as another moment of inspiration from Commons saw him feed Ross Gardner in the box for the midfielder to test Alan Fettis' reactions at the near post.
But Macclesfield were to have the final say before the interval. Neil McKenzie hit the foot of the post with a driven effort and then Macclesfield did find the back of the net.
A neat cross from Paul Harsley picked out Townson's run and the striker provided a calm finish.
Townson should have had a second after the interval but he fired straight at Pedersen when unmarked 12 yards from goal, while Forest's best efforts after the break came from substitute Spencer Weir-Daley who twice threatened from range.