Joe Pigott gave The Dons the advantage shortly after the break but Regan Charles-Cook struck with three minutes to play as it looked like the points would be shared. However, after a number of efforts were repelled, Reilly managed to smuggle the ball home from close range to hand AFC the win which leaves them eight points above the Sky Bet League One drop zone in 19th.
One of the sides below AFC in the table are Southend United after they, with Patrik Gunnarsson in goal, suffered a 2-1 defeat at Oxford United. James Henry and Lewis Gard traded first-half goals, the first of which came from the spot following a foul by Patrik, with the home side netting the winner through Matt Taylor, six minutes from time.
In the National League, Justin Shaibu came off the bench for the final half hour of Boreham Wood's 1-1 draw at home to Hartlepool United. Kabongo Tshimanga lashed The Wood ahead inside 60 seconds but they were pegged back right at the start of the second-half, Gime Toure on target. Sorba Thomas then saw a penalty saved for the home side who slip to fourth after the draw.
Reece Cole and Partick Thistle return to Scottish Championship action on Tuesday at home to Queen of the South.