Chesterfield are through to the JPT final after winning 1-0 at Oldham in the Northern area final second-leg to seal a 3-1 aggregate success.
Oldham dominated most of the game, but veteran Jack Lester sealed the Spireites' success with a late goal.
Oldham were denied by the woodwork after less than three minutes when Shefki Kuqi raced on to Robbie Simpson's pass and crashed his shot against the post from 12 yards.
Filipe Morais and Chris Taylor both brought saves from Chesterfield goalkeeper Tommy Lee, but the home side wasted a string of first-half chances.
Drew Talbot should have scored for Chesterfield just after the restart, only to fire straight at keeper Alex Cisak, but the excellent Lee again did well to thwart Morais and Kuqi.
Lester struck on 88 minutes, bundling into an empty net from close range after a defensive blunder between Cisak and Jean Yves Mvoto.
Chesterfield will face the winner of the Southern Area final at Wembley, with Swindon and Barnet locked a 1-1 after the first leg.