A brace from Jay O’Shea confirmed Chesterfield’s return to League One after a 2-0 win at Burton Albion and sparked the start of the promotion party.
After rivals Fleetwood Town dropped two points at home to Southend United on Saturday, a draw for Spireites would have all but secured a top three spot.
A considerably better goal difference over Fleetwood would have probably seen Paul Cook’s side over the line ahead of Saturday’s clash between the two sides.
But Chesterfield will not have worry themselves with such scenarios after they claimed three points they needed at a rain-soaked Pirelli Stadium on Sunday.
The result not only confirmed automatic promotion in Cook’s first full season in charge of the north Derbyshire club, but also sent Spireites to the top of the table.
Chesterfield had narrowly missed out on the play-offs last time around but a second half brace from O’Shea banished the memories and sent the Blues into dreamland.
Their title hopes were given a boost when Scunthorpe United lost for the first time under Russ Wilcox’s 29-game reign away at Exeter City 24 hours previously.
And the win at Burton, who look ahead to the play-offs, has set up a mouthwatering last game of the season at the Proact Stadium on Saturday, as Chesterfield look to win the League Two championship.
Spireites boss Cook made two changes to the starting line up to that which comfortably overcame Dagenham and Redbridge last Saturday.
Gary Roberts returned to the starting eleven along with O’Shea, as Cook opted for his preferred 4-2-3-1 formation in the penultimate game of the season.
Marc Richards and Dan Gardner dropped to the bench which had a welcomed presence in Drew Talbot, on his return to the first team squad from injury.
A packed away end - boasting 2,000 travelling Spireite fans - roared their team out on to the Pirelli Stadium pitch in the final away game of the season.
Chesterfield were quickest out the blocks with Roberts and Jimmy Ryan keen to get on the ball in the opening exchanges to settle Cook’s side.
It appeared to have the desired effect as the Spireites forced two quick-fire corners - two opportunities to put pressure on the Burton goal - which came to nothing.
Chesterfield kept the ball well and stretched the hosts from left to right but were faced by a well-organised Burton back four marshalled by Marcus Holness.
The hosts began to stem the wave of blue attacks and Billy Kee tried an ambitious effort with his back to goal which looped well clear of Tommy lee’s goal.
Spireites’ pressure almost paid off moments later when O’Shea did well to hold on to the ball before feeding Eoin Doyle, who had pulled away from Holness, but was thwarted by Callum McFadzean’s crucial sliding block on the cover.
Ian Evatt flung himself at an outswinging Roberts corner which sailed over the stands before the first of two injury-forced substitutions were made by Cook.
Gardner replaced on loan winger Dan Kearns in a like-for-like on the right side of Chesterfield’s advanced three midfielders.
O’Shea twice unleashed efforts from the edge of the area - one which flew over and a second that Lee Bell blocked - but keeper Dean Lyness remained untested.
Burton’s front two of Kee and Gary Alexander posed a physical presence to Evatt and Liam Cooper, though the Spireites centre-backs had dealt with the threat.
And, following a tussle between Kee and Cooper, the striker found himself goal-side but instead of taking the ball on threw himself to the floor inside the area.
The officials waved away his appeals but there was bad news for Chesterfield as Cooper was forced off with what looked to be an ankle injury.
Ritchie Humphreys got the nod and took a position in central midfield alongside Ryan as Sam Hird moved in to the back four next to skipper Evatt.
Lyness was forced in to his first save when Roberts fed Doyle, who, from a tight angle, angled a shot towards the far corner the Burton keeper palmed away.
Spireites had gradually built momentum over the first period and came within inches of taking the lead when Hird’s header crashed against the cross bar when he rose to meet Gardner’s in-swinging corner at the back post.
It almost sent the travelling support into ecstasy and produced the goal the game had been crying out for. Chesterfield didn’t have to wait that much longer.
Substitute Humphreys found space on the edge of Burton’s penalty area and slipped an inch-perfect ball through to O’Shea, in space, to pass the ball in to the corner.
Lyness was helpless as the ball hit the back of the net to spark wild scenes at the Pirelli - as fans, players and the coaching staff leapt in to the air in celebration.
Spireites were in dreamland but were almost sent crashing back down to earth when Kee was sent through one-on-one only for Lee to come to the visitors rescue.
Alexander was inches away from latching on to McFadzean’s raking ball over the top before Holness directed his header straight at Lee from a Burton corner.
Roberts had an opportunity to double the visitors’ advantage when he was bundled over by MacDonald 25 yards from goal in front of the away support. The winger dusted himself down and sent a curling effort over the wall which narrowly missed the top corner.
Burton refused to roll over and Bell tested Lee with a fierce, dipping volley Lee from range which dropped just in front of the Chesterfield keeper.
Spireites couldn’t have been accused of taking their foot off the gas as they bombed forward at every opportunity before the killer blow came.
Gardner fed Doyle wide on the right whose cross wasn’t cleared and O’Shea was handed the simplest of tasks of heading in to an unguarded net from within the six yard box to end a two year stay in League Two.