The on-loan Sheffield United winger struck deep into injury time at the Alexandra Stadium after Dario Gradi's side appeared to have nicked the three points with an 89th minute close-range finish from substitute Luke Rodgers.
But it was no more than Roy McFarland's well organised side deserved as they had looked the most enterprising during a dreadful first half in which there was barely a chance of note created.
A strong wind made life difficult for both sets of players and there was a real lack of quality from both forward lines.
Defences were largely on top and Chesterfield's Reuben Hazell did a close man-to-man marking job on Alex dangerman Luke Varney.
Paul Shaw did get an early opening but his shot was deflected past the post.
Crewe took until the 23rd minute before they got anywhere near Barry Roche's goal but David Vaughan dragged a tame shot past the post.
Home captain Jon Otsemobor tried to inspire something when he fired in a low cross but both Rodney Jack and Varney were out of its reach.
Crewe improved after the break and Jack looked like their most likely outlet with occasional bursts of speed.
The West Indian surged to the byline past Alan O'Hare and pulled the ball back only to see Vaughan blaze haplessly over the bar.
The game needed a goal and it got it in the 64th minute when Ryan Lowe produced a neat flick to play in Varney. The striker mis-hit his shot but keeper Roche was badly positioned and the ball sailed past him into the far corner.
The game instantly livened up and Colin Larkin cracked a volley which glanced off the far post, while at the other end Jack's snap-shot cannoned off Roche's left-hand post.
Crewe were never assured though of taking maximum points with such a slender margin and they were distinctly off colour.
Derek Niven came up with an equaliser five minutes from time when a lay-off from Paul Hall ushered him in on the right side of the box. The Scot finished with a fierce drive across keeper Stuart Tomlinson.
Gradi reacted by bringing on Rodgers and Michael Higdon and it was Rodgers who turned in a low shot amid a goalmouth melee.
However, Chesterfield were not finished when substitute Wayne Allison's cross was only headed as far as Hurst and he rammed it back underneath a sea of legs and into the bottom corner for the vital equaliser.