The Spireites came from two goals down with ten minutes of second half magnificence to defeat Yeovil Town 3-2 at Huish Park.
Three goalscoring minutes before the hour mark saw Sam Foley double the Glovers' lead before moments later Sam Hird thumped home a header from Gary Roberts' fine cross to pull the score back to 2-1.
With 67 minutes gone the Spireites grabbed the leveller they had more than warranted when a moment of individual brilliance from substitute Jay O'Shea saw the Irishman pummel a stunning strike into the top corner from 20 yards.
This Good Friday Sky Bet League 1 fixture was to be contested by two sides at either end of the table, as Paul Cook’s Chesterfield made the 214 mile trip to the south coast in anticipation rather than expectation on the final leg of the season.
Early pressure from the Spireites brought a whole host of corners in the opening period of the game, but converted left-back Drew Talbot was unable to capitalise on the best opportunity, as his cannonball from 12 yards out struck fellow defender Hird on its way wide.
Despite the positive start from Chesterfield, it was Yeovil’s Liam Shephard who came within whiskers of opening the scoring, as his driving run towards Tommy Lee’s goal created space for a shot, but his effort narrowly missed the target.
Following the Spireites’ bright start, a shift in momentum saw the Glovers take control of the game and yet again the hosts nearly opened the scoring, this time in spectacular fashion, when former Crewe Alexandra youth product Ajay Leitch-Smith cracked a volley from 30 yards out, but with Lee beaten, the post was also.
However the hosts did break the deadlock not long after, as the experienced forward Hayter latched on to an eye-of-the-needle Foley through ball, before Yeovil’s number nine calmly slotted the ball under Lee and into the net.
Chesterfield were looking for a swift reaction, and they came within the width of the post of doing so immediately, as Roberts’ inswinging free-kick found Talbot unmarked at the back post, but his goal-bound header was brilliantly tipped onto the woodwork by Artur Krysiak.
The Spireites continued to carve through the Glovers’ defence with ease at times, and after superb approach play down the right flank, Tendayi Darikwa’s well-measured pass found Bryron Harrison, but the striker was unable to repeat his midweek goal at Bradford as Krysiak poked the ball away.
Chesterfield were putting on a show for the travelling fans despite being one down, and it was the woodwork which came to the Glovers’ rescue again, as Jimmy Ryan’s cross-shot looked destined for the top corner, but the crossbar saved Yeovil again.
The Spireites resumed the second period on the front foot, with Darikwa replicating his menacing ways in the first-half, as in the opening seconds the full-back raced down the right and met Roberts’ cross sweet on the half-volley, but his vicious effort only grazed the top of the bar.
However, it was Yeovil who grabbed the second goal of the afternoon and doubled their lead, as Foley’s late run from midfield bamboozled the Spireites backline and he pounced on Shephard’s lofted pass before striking the ball on the stretch into the bottom corner.
Chesterfield nearly hit back instantly after Yeovil’s first goal, but this time they did manage to do so immediately, Roberts’ set-piece on the far side found Hird with the freedom of the penalty area, and the defender headed in his second goal in three games to give Chesterfield a lifeline.
After the Spireites’ domination they would have felt hard done by to find themselves a goal down even after Hird’s header, but substitute O’Shea changed that as he drew Chesterfield level just six minutes after equalising.
A sensational turn on the edge of the area from the Irishman created the space for the Spireites’ number ten, before he unleashed a venomous effort which flew into the top corner.
O’Shea’s equaliser saw him snatch the reputation of being the supersub on this Friday afternoon, and just minutes later O’Shea sent the travelling supporters into ecstasy as he doubled his tally and completed a fantastic comeback for Chesterfield.
The two substitutes, O’Shea and Gboly Ariyibi, combined as the latter crossed for the Irishman to perform a stunning acrobatic volley which flew into the corner, giving the Spireites their first lead of the afternoon.
The dramatic revival from the Spireites appeared to crush the confidence of the relegation-threatened Yeovil, as Chesterfield marched on to end the afternoon with a four-point gap between themselves and seventh place.
Yeovil Town: Krysiak (gk) - Webster (c), Sheehan (Berrett 70’), Shephard, Arthurworrey - Foley, Twumasi, Kingsley, Ugwu - Hayter, Leitch-Smith (Grant 64’)
Subs not used: Bell, Berrett, Moore, Ralph, Stewart, Eastmond
Chesterfield: Lee (gk) - Darika, Hird, Evatt, Talbot - Morsy (c), Humphreys (O’Shea 45’), Ryan, Roberts, Clucas - Harrison (Ariyibi 45’)
Subs not used: Banks, Raglan, Jones, Gnanduillet, Dieseruvwe
Yeovil Town: Hayter 19’, Foley 57’
Chesterfield: Hird 59’, O’Shea 66’ 70’
Attendance: 4,520 (432 away supporters)