Will Grigg found the back of the net with a crucial goal to help Chesterfield secure a 1-0 victory over Accrington, clinching the final play-off position in League Two.
Starting the day in ninth place, the Spireites needed other results to go their way, with Salford and Grimsby not winning, while they had to at least draw against Accrington at the Wham Stadium.
Despite a late scare with Accrington hitting the woodwork twice in added time, Chesterfield managed to hold on to claim the seventh spot in the league table.
The decisive moment came in the 32nd minute when Jenson Metcalfe's shot was parried by Michael Kelly, only for Ryan Colclough to hit the post before Grigg pounced on the loose ball to score into the empty net, marking his 14th goal of the season.
Grigg continued to threaten, forcing a save from Kelly early in the second half, while Colclough and Tom Naylor missed chances for Chesterfield.
Despite Dylan Duffy hitting the crossbar for Chesterfield in the 87th minute, Accrington pressed on, with Josh Woods and Anjola Popoola both hitting the woodwork in the dying moments of the game.
Chesterfield held on in a tense finish and will now prepare to face Walsall in the upcoming play-offs.