Spireites captain Charlie Wakefield scored the only goal of the game, as ten-man Chesterfield defeated Buxton 1-0 at Silverlands, to reach the final of the Derbyshire Senior Challenge Cup.
Wakefield followed up goalkeeper Jan Budtz's clearance with a fine first-time effort in the 51st minute to seal the progression, before striker Levi Amantchi was sent off for an off the ball incident 20 minutes later.
The Spireites started brightly, with Ify Ofoegbu and Amantchi looking lively in the opening stages.
The duo combined in the eighth minute, when Ofoegbu squared the ball across the penalty area to Brandon Howard, the winger then laid the ball off to Ricky German, who turned his man before seeing his left-footed effort palmed around the post by Budtz.
More good play from Chesterfield eight minutes later, saw captain Wakefield skip past his man in midfield, he then found Ofoegbu who hit a fierce drive just over the bar.
At the other end, Ryan McDermott’s cross found Andy McWilliams unmarked but the winger missed his kick and the Spireites cleared.
Budtz was called into action again in the 21st minute, when Jack Brownell’s pass found Ofoegbu, who then wriggled free from the full back and shot left footed, Budtz then got down quickly to save with his feet.
Buxton’s best chance of the half came when Liam Hardy latched on to a through ball, he then took the ball around Dylan Parkin, who had vacated his line quickly.
Hardy then tried to lay the ball back to a team mate, but Dylan Hand was in the right place at the right time to put the ball behind for a corner, which was headed away by Alex Render.
That proved to be the last real action of the first half, with the teams going in level at the break.
The Spireites didn't have to wait long after the re-start for the opening goal.
Marshall Willock's pass was chased after by German, but he was beaten to the ball by Budtz, his clearance fell to Wakefield who struck a beautifully weighted lob into the right-side of the net.
Hardy then went close with a free kick, but fortunately his effort ended up wide of Parkin's right-hand post. At the other end Chesterfield appealed for a penalty after German was fouled by the goalkeeper, however the referee waved play on, much to the frustration of the Spireites' bench.
Parkin made his first real save of the night in 65th minute, when after Willock had headed away a free kick, substitute Joe McGee fired a half volley straight at him from outside the box. A minute later, Amantchi and Ofoegbu linked up again on the left, the latter found Wakefield whose first-time cross was then headed wide by German.
There was controversy in the 72nd minute when Amantchi and Nico De Girolamo collided off the ball, De Girolamo went down and the Spirietes' striker was shown a straight red card! Two minutes later, Wakefield came close to his second of the night, when he was put through on the host's goal, he then tried to lift the ball over Budtz, who denied him with his legs.
Buxton then squandered a huge chance to draw level in the 82nd minute, when De Girolamo headed wide from the penalty spot after being found unmarked from a left-wing cross.
Brownell then almost got a second for the Spireites, when his effort was palmed wide by Budtz. In stoppage time, Brownell fed Zak Walker on a counter attack, the substitute then slotted the ball into the net, but it was ruled out for offside.
It didn't matter however, as shortly afterwards the referee blew for full time and confirmed the Spireites' place in the final, where they'll meet either Ilkeston or Alfreton Town who play next Tuesday.
Buxton: Budtz, Baker, Amos, Ravenhill (C), De Girolamo, Maguire, McDermott (McGee 57'), Boradhead, Taylor (Meade 40’), Hardy, McWilliams (Emerson 77').
Substitutes not used: Miller, Needham.
Chesterfield: Parkin, Hand, Render, Willock, Sharman, Brownell, Howard (Sennett-Neilson 78'), Ofoegbu (Walker 87'), German (Holmes 85'), Wakefield (C), Amantchi.
Substitutes not used: Jones (gk), Emery.