The decisive moment came when James Dayton played in Holman who smashed the ball past Richie Branagan.
Amari Morgan-Smith had his strike saved as the Robins threatened to extend their lead, while Chris Holroyd saw the hosts' best effort saved.
Cheltenham will top 100 points if they win against Lincoln next week while Macclesfield remain 10th.
Dan Holman scored the only goal as National League champions Cheltenham won at Macclesfield.