Skipper Jimmy Smith scored arguably the most important goal of his Crawley career deep into stoppage time as Reds secured Football League status in dramatic style.
Having led 2-0 through a double by James Collins, Crawley found themselves 3-2 down on the hour to play-off chasing Carlisle.
But with seconds remaining, Joe McNerney cushioned a header from Andre Blackman’s diagonal ball into Smith’s path and he smashed a right-foot volley inside
Mark Gillespie’s right-hand post to spark the biggest celebration at the Checkatrade for quite a while.
It lifted Crawley to 19th in the table, seven points clear of second-bottom Hartlepool who have dropped into the bottom two with two games to go.
Reds can now enjoy the finale to the campaign and start to plan for next season, although going into stoppage time it looked as if safety might not be assured for at least another week.
It had all started so well. Collins put Reds in front in the 12th minute with an outstanding strike from 25 yards into the top right-hand corner after Blackman’s pass into space had set up a shooting opportunity which the striker took with aplomb.
Thirteen minutes later Collins became only the second Crawley striker to score 20 League goals since 1986 when he coolly converted a penalty after he’d been poleaxed in the box by Gillespie.
But Carlisle’s 3-5-2 formation caused Reds problems throughout and things started to go wrong when first Mark Connolly (illness) and then goalkeeper Glenn Morris, whose cut head opened up, had to go off – Morris when he tried unsuccessfully to stop Jabo Ibehre from making it 2-1 in the 28th minute after Reds failed to deal with a routine ball down the middle.
Reggie Lambe fired over when clean through but Carlisle, who had also hit the post through Jamie Devitt, levelled on 42 minutes when ex-Red Jamie Proctor powered home a header from Macualay Gillesphey’s diagonal ball from the right.
The momentum was now with the visitors and they took the lead in the 59th minute. A long ball from the left split open the home defence and Lambe strolled into acres of space before rolling the ball past Mersin and into an empty net.
Things looked bleak but Reds regrouped. Smith fired wide from a decent position, Josh Payne drove a shot just past the left-hand post and saw another volley saved by Gillespie before Collins headed a cross onto the top of the net.
It looked as if Reds had run out of time but skipper Smith had other ideas and the celebrations which followed – both on the touchline and in the stands – showed just how much it meant.
Reds: Morris (Mersin 32), Young, McNerney, Connolly (Yorwerth 27), Blackman; Boldewijn, Smith, Payne, Djalo (Roberts 69), Cox; Collins. Unused subs: Harrold, Clifford, Lelan, Murphy.
Booked: Smith, Payne
Attendance: 2003 (224 Carlisle)
Man of the match: James Collins