Reviving Port moved to within a point of League Two safety as second-half strikes from Harrison Biggins and Michael Spellman hauled them off the bottom of the table, as joy abounded at blustery Rodney Parade.
It was a stormy afternoon at NP19 but the leaden skies failed to supress the delight of an almost 4,500 gate who celebrated a successive home victory roaring, "We are staying up" with the beat of Gala's 'Free from Desire' booming across the pitch.
Fellow strugglers Crawley might have snatched a late winner at free-falling Barrow, but rising County have now leapfrogged Harrogate and are breathing down the neck of 22nd-placed Bristol Rovers who they meet in a Seven-side showdown in front of the Sky Sports cameras at the Memorial Stadium next Saturday lunchtime
Newport have lost 16 points from winning positions so far this campaign, but there was no bitter cup of sorrow here, as skipper Matt Baker and Ryan Delaney led manfully from a back-four that was superbly protected by the outstanding Ciaran Brannan and energetic Biggins.
Republic of Ireland product Brannan was most certainly a candidate for the Man of the Match accolade that was handed to goal-scorer Spellman. - yet it was the former Sheffield Wednesday star's suppression of the Spireites' inventive midfield that was the bedrock for this critical triumph.
Fit-again Chesterfield substitute Dilan Markanday pulled a goal back for his Spireites late on to set up a grandstand finish, but Christian Fuchs' men were in no mood to yield - the Exile's black and amber defensive line holding firm.
County made just the one alteration to the side who were most unfortunate to fall late 3-2 at Gillingham last Saturday - effective Brennan moved in to anchor midfield, as consistent centre-back Lee Jenkins dropped to the bench.
There were glorious home debuts for midfield power-house Biggins and left-side defensive stopper Delaney, a returning Port favourite, borrowed from Shrewsbury and Swindon respectively in the January window.
Paul Cook's Spireites, who spied the play-off shake up, saw a flurry of alteration. Ex-Sunderland raider Will Grigg led the attack, supported by former Rotherham front-runner Freddie Ladapo, Tom Pearce slotting in at left-back. Blonde linkman Sammy Braybrooke was a familiar face in the visitor's line-up, the on-loan Leicester player had enjoyed donning County colours earlier in the season, of course.
Chesterfield boasted a potent clutch of goal-power, amongst their substitutes - ex-Blackburn attacker Markanday and Armando Dobra, formerly of Ipswich, restored after injury problems.
A pre-match on-pitch appearance of former Exiles manager Michael Flynn, who had been inducted into Newport County AFC Hall of Fame before this clash, raised home cheers and the action sparked in the seventh minute as Port's Biggins saw yellow for grounding Spireites' Sam Curtis with a robust challenge.
Chesterfield poured forward seeking that early breakthrough. James Berry's searing pace took him past Liam Shephard, the borrowed Wycombe man's angled delivery finding Ladapo, who saw his low effort deflected wide via County keeper Jason Wright's right boot.
Yet a superb move so nearly opened up the Spireites on 23 minutes. Spellman picked the pockets of Braybrooke, the Geordie then releasing Bobby Kamwa whose right-footer flashed across the goal with Zach Hemming scrambling to cover.
The men from Derbyshire should have pulled ahead four minutes later, though. Grigg's intricate pass unlocked the menacing Berry, another slide-rule delivery from the player deep in the box, somehow lifted over the top by Liam Mandeville.
It was an astonishing miss from the ex-Doncaster raider and, despite the teeth of stiff wind gusts in their faces, County were to administer punishment for the misdemeanour. Kamwa's trickery took him around Curtis and Braybrooke, all-action Biggins then seeing his blast cannon wide with Chesterfield at full alert.
Leaping Delaney glanced the resulting Matt Smith corner past the far post and Spellman brought Hemming to his knees as the first-half closed - County clearly troubling opponents 16 spots above them in the section.
Sheer momentum powered Fuchs' warriors ahead in the fiftieth minute. Seconds after seeing his dipping blast tipped over the bar by Hemming, Biggins ghosted behind Chesterfield skipper Kyle McFadzean to poke Anthony Glennon's in-swinging corner into the net.
It was Biggins' first-ever strike for County, and ended the Yorkshireman's 20-month goal drought. There was even more joy for rampant Newport as they doubled their advantage on 63 minutes - impressive Spelllman's sweet 18-yard left footer flashing past rooted Hemming.
The Exiles sought to damage the Spireites further as the prolific James Crole entered the fray, replacing Nathan Opoku, County almost adding a third, Kamwa's overhead kick sailing narrowly off target.
Chesterfield were desperately looking to regroup - Markanday, Dobra, Dylan Duffy, Lee Bonis and Tom Naylor all introduced off the bench by the 76th minute.
The visitors had hacked a lifeline with five minutes remaining - sub Markanday profiting from Pearce's pinpoint right-side corner, setting up a nail-biting finale in the elongated added time, a succession of Spireites' set pieces amounting to nothing, as County held on with a minimum of drama.
Newport County [4-3-3]
Jordan Wright
Liam Shephard
Ciaran Brennan
Matt Baker [C[
Ryan Delaney
Anthony Glennon
Matt Smith
Harrison Biggins
Michael Spellman
Bobby Kamwa
Nathan Opoku
Subs
Nik Tzanev [GK]
Cameron Evans
Joe Thomas for Kamwa 90 mins
Lee Jenkins for Biggins 80 mins
James Crole for Opoku 69 mins
Ben Lloyd
Tanatswa Nyakuhwa for Spellman 90 mins
Chesterfield [4-2-3-1]
Zach Hemming
Sam Curtis
Kyle McFadzean [C]
Sil Swinkels
Tom Pearce
Sammy Braybrooke
Ryan Stirk
Liam Mandeville
James Berry
Freddie Ladapo
Will Grigg
Subs
Tom Naylor for Stirk 79 mins
Lee Bonis for Ladapo 66 mins
Dylan Duffy for Berry 75 mins
Armando Dobra for Grigg 75 mins
Vontae Daley-Campbell
Dilan Markanday for Mandeville 75 mins
Will Dickson
Referee: Declan Brown
Assistants: Ashley Allen & Daniel Robinson
Fourth Official: Keiran Forrest
Attendance: 4,355 [458 ]
