Aldershot started brightly despite playing their last competitive fixture three weeks ago.
On 15 minutes, Chris Blackburn cut in off the right wing and fired from 20 yards, but Jonny Brain saved smartly to his left to thwart the danger.
Having run Everton close in the FA Cup, Macclesfield showed Premier League class to get in front at the end of the first quarter with their only first half chance.
Hudson back heeled straight to Jamie Tolley trying the keep the ball in play.
The midfielder drove 50 yards into the Aldershot box and delivered a pinpoint pass to Gareth Evans and the striker calmly slotted the ball into the bottom corner.
On 34 minutes, Brain produced a great save from Danny Hylton's point-blank header.
From the subsequent corner, Rhys Day headed over from 12 yards with time and space on his side.
As the half closed out, Andy Sandell forced another superlative save out of Brain.
Blackburn lobbed to Sandell, the winger fired on the volley from 20 yards but was denied by the out-stretched fingers of the goalkeeper.
Evans should have finished the game at the start of the second half.
Nottingham Forest loanee Emile Sinclair showed good awareness too find Evans inside the penalty area, but the striker fired an easy chance wide.
The home side continued to press and Ben Harding was then denied by two more excellent Brain saves.
With 15 minutes left, Brain tipped Harding's piledriver onto the bar and seconds later the former Port Vale goalkeeper clawed another Harding effort around the post.
On 80 minutes, Izak Reid countered from the edge of his own box forcing Nikki Bull to make his only serious save of the match.
In injury time and with Aldershot growing increasingly desperate, Hudson picked up a loose ball on the edge of the penalty box and smashed his drive into the top corner to give the home side a deserved share of the points.