Lee Novak and Jordan Rhodes showed some quality in front of goal as two quick first half efforts sunk Chesterfield.
Spireites had plenty of possession throughout but lacked the power when it really counted.
John Sheridan brought in Nathan Smith to replace the ineligible Liam Ridehalgh at left back whilst Alex Mendy and Craig Westcarr replaced Danny Whitaker and Jack Lester.
Midfielder Mark Allott made his 335th league appearance for the club lifting him above 1980s and 90s defender Lee Rogers into 13th spot on the all-time list.
Chesterfield opened well and slung in plenty of crosses into the box ahead of a couple of Huddersfield corners that were well defended. Jordan Bowery got in the first effort on target but Alex Smithies saved well and moments later he spilled a Mendy long ranger that had to be hacked clear for a corner by Tom Clarke.
Two quick goals then changed the complexion of the contest. Novak’s superb finish, his 13th goal of the season, a right-footed half-volley from the box edge, was Terriers’ first effort on target after an Anthony Kay assist.
Tommy Lee had to block a Rhodes effort but seconds later ex Spireite Jack Hunt crossed in and the striker hit first time to register his 34th strike of the campaign and give the scoreline a look that didn’t match the hosts’ early endeavours.
Westcarr’s header just over as half-time approached reminded Terriers, who were now playing with confidence, that Spireites were still in the game. But before the whistle Rhodes hit wide from a decent position and Gary Roberts hit the bar following a quick break confirming to the crowd their pedigree.
Roberts’ cross soon after the break was blocked by Lee at the expense of a corner as Spireites struggled to breach the visiting back line though Franck Moussa shot wide after solid Mendy play.
Neal Trotman bundled the ball wide from a Westcarr free-kick and the latter glanced a header wide as Chesterfield continued to battle. Spireites were delivering plenty of ball into the box but the deliveries lacked genuine quality and rarely led to trouble for Smithies.
Nicky Ajose saw a shot blocked and Drew Talbot headed just over as the game drew to a close with the table looking distinctly unhealthy for Sunday’s visitors to Wembley for the JPT final.
Chesterfield (4-4-2): Lee 6, Hurst 6, Trotman 6, Thompson 6, Smith 7, Talbot 8, Moussa 6, Allott 7 (Ajose 72, 6), Mendy 7, Bowery 6, Westcarr 7. Subs (not used): Fleming, Ford, Whitaker, Lester.
Huddersfield (4-4-2): Smithies 6, Hunt 6, P.Clarke 7, Morrison 6, T.Clarke 6, Roberts 8, Kay 6, Gudjonsson 7 (Arismendi 78), Ward 7, Novak 7 (Lee 70, 6), Rhodes 7 (Cadamarteri 89). Subs (not used): Bennett, Arfield.
Goals: Novak 23, Rhodes 27
Referee: Chris Sargison (Staffordshire)
Bookings: Kay (Huddersfield)