Chester shipped a painful equaliser in the dying seconds as Guiseley grabbed a last-gasp point at Nethermoor Park.
Starting the day eight points adrift of safety and looking to avenge their Boxing Day defeat at the hands of the same opponents, Kingsley James’ goal on the hour mark looked to have given Marcus Bignot’s side a vital three points in their battle to avoid the drop.
However, there was late drama as Guiseley’s Ash Palmer blasted home an injury-time leveller with virtually to last kick of the game to break Blues’ hearts, leaving Bignot’s side with a mountain to climb if they are to retain their National League safety.
Bignot opted to make four changes from the side who had been beaten six days earlier by the Lions, with Andy Halls, Paul Turnbull, James Akintunde and skipper John McCombe returning in place of James Jones, Tom Shaw, the injured Ross Hannah and suspended left-back Lathaniel Rowe-Turner, who was needlessly sent off for a two-footed lunge on James Roberts in the reverse fixture.
Jordan Archer and Myles Anderson were also both injured and failed to make the match-day squad.
The visitors began the brighter and it was a foul by Jordan Gough 25 yards out which gave Callum McFadzean the chance to deliver but Sam Hornby gathered comfortably.
Turnbull had the Blues first meaningful chance of the game on seven minutes and he blasted a low drive well wide from 20 yards after a misplaced headed clearance from Palmer.
Hornby was called into action on nine minutes as he rushed out from goal to deny the run of Rowan Liburd who was looking to nip the ball past the Blues' goalkeeper.
Chester – all in yellow – created a good opening on 10 minutes as Turnbull's long ball forward was chased down by Akintunde, who forced a throw-in off Jonathan Maxted's clearance.
Akintunde was then back in the midst of the action as he headed down Halls' cross from the right wing, taking a deflection off Palmer and eventually grasped by Maxted.
Guiseley striker Roberts – so impressive against the Blues earlier in the week – latched onto a through ball but Astles shielded him out of play for a goal-kick.
Paul Cox's hosts looked the more threatening of the two teams however and it was Liburd who crashed a shot against the crossbar on 17 minutes, holding off Astles' challenge and thrashing a right-footed drive off the underside of the upright with Hornby well beaten by the power of the shot.
Roberts almost gave Guiseley a deserved lead on 22 minutes after Hornby fumbled at a corner but the forward's right-footed effort was blocked by a combination of McCombe and his team-mate Liburd.
Harry White was unfortunate to be penalised for a foul on Simon Lenighan on the 25 minute mark, with the resulting free-kick cut out by Kingsley James, who launched a counter-attack but Akintunde couldn't get on the end of the ball forward.
Halls felled Roberts on the edge of the area but the striker strode up and blasted the resulting free-kick well over the bar.
With the rain now teeming down, Gough whipped in a ball from the right flank with his left foot but James failed to latch onto it at the back post.
Turnbull's clever ball forward found White, who laid it off for James who in turn crossed for Akintunde who couldn't finish the move off at the back stick.
Roberts was presented with an excellent opening on 39 minutes as Turnbull's misplaced back-pass was gathered by the Lions' forward but his 18-yard low shot was well held by on-loan Port Vale stopper Hornby. White then chased down a loose ball at the other end, span past Palmer, but dragged his effort well wide.
Guiseley were forced into a 42nd minute change as Alex Lawlor went down injured and was replaced by defender Jean-Yves Koue Niate, as White nearly got on the end of a deep cross from the left wing by Gough.
Chester were immediately into the action after the half-time break as Turnbull nearly got on the end of Reece Hall-Johnson's cross from the right, before Lucas Dawson provided a timely intervention at the other end to deny Roberts.
Hornby flapped at a corner from Alex Harvey but referee Matthew Diccicio blew for a foul inside the area but it was the hosts in the ascendancy as Roberts nearly got on the end of Liburd's square ball across goal.
Halls cross from the right-hand side found James via a deflection and the 25-year-old's miscued shot found Halls again at the far post but his shot was blocked for a corner.
From Turnbull's resulting out-swinging delivery, Astles thought he'd handed Chester a precious lead after he stabbed the ball home at the far post with Maxted caught out by the flight of the ball, but referee Diccicio consulted with his assistant referee and ruled that the goalkeeper Maxted had been fouled in the process, much to the disgust of the Blues' players.
Chester grabbed a deserved lead on the hour mark. Akintunde did very well to hold the ball up after Dawson's ball forward, holding off the challenge of Palmer, turning and laying the ball to James inside the area, who ran onto it and calmly slotted a fine left-footed finish into the bottom corner, finally giving the travelling Blues supporters something to cheer after a dismal festive period to-date.
Daniel Udoh was sent on to replace White who had run himself into the ground and certainly gives the Blues an outlet up front.
Halls then picked up his ninth yellow card of the campaign with a rash lunge on MacFadzean on the left wing, the midfielder picking himself up to delivery a deep cross which Liburd couldn't convert under pressure from McCombe. The veteran centre-half was handed a surprise recall but more than justified his selection alongside Astles, a timely return to his best form.
Udoh was chasing down every loose ball and a run into the corner saw him lay the ball off for Turnbull 30 yards out but he rushed his shot and skied it over the bar.
It was Hornby to the rescue in the closing stages as Mike Fondop rose above the Blues' defence on 84 minutes and headed firmly into the corner of the goal but the Blues' stopper produced a superb save to parry the effort to safety.
Craig Mahon and Shaw were sent on to add some further experience to try and see the win out as the Lions kept pushing for a leveller, but it was a dogged rearguard effort from the Blues' defence.
As the clock ticked into stoppage time, MacFadzean's long throw wasn't fully cleared by Halls and Astles and after a scramble in the area, the ball fell to Palmer who smashed his shot home with virtually the last kick of the match. A desperately bitter pill to swallow for the Blues.