Just when it seemed the Silkmen had done enough to secure a point in their first match with caretaker boss Ian Brightwell at the helm, they were undone right at the death by a speculative 25-yarder from Shrewsbury's central defender Kelvin Langmead, which shot past the unsighted Macclesfield 'keeper Tommy Lee.
It was rough justice for the visitors, who had fought back from the first minute blow of conceding a goal to midfielder Ben Herd, to level 11 minutes after half-time through Spencer Weir-Daley.
Macclesfield then had the impressive Martin Bullock red carded for a second bookable offence, but seemed to have safely negotiated their way through the closing stages to earn the point their efforts deserved.
But deep into stoppage time up popped Langmead to bolster Shrewsbury's promotion charge, leaving Macclesfield rooted firmly to the foot of the table.
Brightwell, in charge of first team affairs after Brian Horton was sacked last weekend, could not have made a worse start to his managerial career, seeing his side fall behind inside the opening 60 seconds. Shrews' striker Andy Cooke shrugged off a couple of weak tackles and, although he lost possession, the ball rolled to Herd who side-footed home from 10 yards.
Boosted by their early breakthrough, Shrewsbury continued to press with Cooke, Steve Leslie and skipper Richard Hope all going close to increasing the lead.
But after the break Shrewsbury were unable to find any momentum and as the visitors grew in confidence began to carry more of a goal-threat and deservedly levelled on 56 minutes when Weir-Daley scored with an angled drive from 12 yards.
Their joy was cut short, however, on 66 minutes when the influential Bullock was ordered off after he was adjudged to have dived in the penalty area, earning a second yellow card to the one he had received in the first half.
Macclesfield, who survived the 86th minute scare of Stewart Drummond hitting a post with Lee beaten, were within seconds of securing a point, when Langmead picked up as loose ball before driving it goalwards through a crowd of players and past the startled Lee.