Chesterfield face a replay in the FA Cup after being held to a 1-1 draw by lower league Billericay in the first round proper.
The Spireites were dominant for large parts of the tie and created plenty of chances, but were held out by an in-form goalkeeper and some desperate defending.
Laurence Maguire's header put the hosts ahead in the first half, but a beautiful long range goal from Moses Emmanuel after the break earned the National League Side side the chance to do it all again at the AGP Arena.
The visitors should perhaps have taken the lead inside two minutes, a clever reverse pass splitting the Spireites back line and putting Moses Emmanuel through, only for Callum Burton to deny his shot.
Chesterfield had an early chance of their own, their second corner of the game finding Laurence Maguire all alone at the back post, the centre-half's goalbound header saved by Alan Julian.
Martin Allen had hinted before the game that he would go with his more 'technical' attackers and they linked up well on eight minutes, Zavon Hines' cross headed goalwards by Marc-Antoine Fortune, Julian saving again.
Jonathan Smith's anticipation allowed him to nip in and rob Jake Howells on halfway, starting a Town attack that ended in another stop from the Billericay keeper, this time from a low blast by Hines.
The goal their good start deserved arrived on 17 minutes when all the hard work done on set-pieces finally paid off.
Joe Rowley fizzed a free-kick to the back post and Maguire rose highest to glance a fine header into the bottom corner of the net.
Billericay gradually grew into the game after conceding and began to get some joy on the flanks, attempting to exploit Town's lack of width.
But it was through the centre their best effort came, Sam Deering running through an acre of space in the middle, with the Town defence backing off, before flashing a shot just past the post.
And with two minutes remaining in the half Joseph Kizzi went on an overlap on the right, took the ball into the area and passed it right across the six-yard box, none of his team-mates taking advantage.
Chesterfield made a bright enough start to proceedings after the break, but still found themselves pegged back on 52 minutes.
A free-kick, conceded by Curtis Weston on halfway, was taken swiftly by the visitors and Emmanuel had time and space to set himself from 25 yards before unleashing a wonderstrike that gave Callum Burton no chance.
Chesterfield recovered from the blow and began to put real pressure on Billericay, Jonathan Smith forcing Julian into a good save with a header before Fortune and Hines both saw shots blocked.
Martin Allen made a double change midway through the half, replacing Kyel Reid and Fortune with Lee Shaw and Levi Amantchi.
Town were firmly on top, barring the odd foray upfield from Billericay, and came close to going ahead when Shaw pulled the ball back for Maguire, following a corner, and the defender blasted over the bar.
The Spireites continued to knock at the door, Binnom-Williams finding Smith in the box, the midfielder's shot deflected wide. Seconds later Weston curled past the upright and then Shaw got in on goal, only for Julian to thwart his effort.
With four minutes remaining Tom Denton was sent on for Weston to give the home side an added aerial threat.
Town pushed and pushed for a late winner and it looked certain to arrive when Shaw found Hines on the penalty spot, but Julian produced another fine stop to ensure it ended 1-1.
Chesterfield: Burton, Evans, Binnom-Williams, Hollis, Maguire, Rowley, Weston (Denton 86), Smith, Reid (Shaw 66), Hines, Fortune (Amantchi 66). Subs: Anyon, Muggleton, Nelson, Kiwomya.
Billericay: Julian, Kizzi, Kennedy, Doe, Hayles (Inman 35), Emmanuel (O'Hara 70), Howells, Waldren, Lafayette, Deering, Robinson (Jahraldo-Martin 60). Subs: Wells, Modeste, Shokunbi, Hunte.
Referee: Mr Martin Wood. Assistants: Mr David Hunt, Mr Nicholas Hawksy.
Goalscorers: Maguire 17; Emmanuel 52
Attendance: 2,952 (255 away)