Swindon's mixed start to the season under Paolo Di Canio continued as they were beaten at the Moss Rose.
Second-half goals from Macclesfield duo George Donnelly and Ross Draper were enough to condemn the Robins to a fifth League Two defeat in six away matches.
On-loan Donnelly put Macclesfield ahead on 62 minutes with a 40-yard run and low shot, his first goal for the club.
A powerful bullet drive from midfielder Draper sealed victory for the Silkmen seven minutes from time.
Di Canio was left cursing referee Steve Rushton when Swindon playmaker Matt Ritchie danced past keeper Jose Veiga only to have his heels clipped.
The youngster lost his momentum but the referee waved away appeals for a penalty as he stayed on his feet.
To further frustrate Swindon's Italian boss, the visitors had dominated the first half, home keeper Jose Veiga making two important saves from Raffaele de Vita, first palming a shot onto the post and then clawing wide a powerful low drive.