Crawley were relegated to League Two in front of a sell out crowd after two goals in the last 15 minutes earned Coventry City the win that secured their survival.
Things looked to be going Reds’ way when Brian Jensen saved a first-half penalty and Mathias Pogba put Crawley ahead in the 47th minute with a powerful header.
But Marcus Tudgay equalised with 15 minutes to go and as Reds pushed forward for the winner they needed they were hit on the counter by a goal from James Maddison.
It means Reds drop down to League Two after three years in the third tier. They were joined in the drop by Notts County, Leyton Orient and Yeovil Town.
Interim Manager Dean Saunders named the same side that came so agonisingly close to securing their League One status last week in the 4-3 defeat to Peterborough.
There was an early scare for Reds on four minutes when Coventry had the ball in the net. John Fleck’s free-kick was bundled into Jensen’s goal but was ruled offside by the linesman.
Tony Mowbray’s men began the game well and were seeing plenty of the ball in Crawley’s area in the opening ten minutes.
Reds first effort came on 12 minutes after strong hold-up play from Pogba. The ball found its way to Kelly Youga, who cut in from the left and fired a shot over the City goal.
Both sets of players took a while to get used to the conditions as the slippery surface caused problems with ball control.
Crawley were looking very positive in the opposition half and drew plenty of fouls just outside the penalty area. Reds’ main threat were balls to Izale McLeod and Pogba, who did well to hold up and bring others in to play.
The skipper was looking as lively as ever leading the line and was chasing everything and putting the Sky Blues’ defencer under pressure.
Reds worked a good opening just before half-time as Lewis Young and Marvin Elliott linked up down the right. Elliott found himself just outside the six-yard box, but his angled drive was held by Lee Burge.
The first half drama wasn’t over yet, as Tomlin tripped Marcus Tudgay in the area. Nick Proschwitz stepped up to take the spot kick, but was denied by Jensen with a superb save down to his right.
Reds came out of the changing room displaying real intent from the off and were in front on 50 minutes. Youga and Tomlin combined down the left and the midfielder whipped in an inch-perfect cross for POGBA to head in to the top corner.
The lead was nearly doubled a minute later as top scorer McLeod latched on to Darren Ward’s long ball. The captain did well to get his effort on target, but he couldn’t beat Burge at his near post.
The sun came out for the second half and the atmosphere around the ground lifted as the Reds kept Coventry penned into their own half.
Coventry enjoyed a spell of possession after the opener and went close on 62 minutes when substitute Maddison’s shot flew past Jensen’s goal into the Bruce Winfield Stand.
The visitors were level on 72 minutes with an almost identical goal than the one scored at the other end. Captain Jim O’Brien swung in a ball from the right hand side and TUDGAY was there to head past Jensen.
As the game headed into the last ten minutes Saunders brought on Gwion Edwards and Bobson Bawling to increase the attacking options.
But there was heartbreak for Reds fans in the 90th minute as Nouble read Ward’s back pass and found MADDISON unmarked on the six-yard line. The substitute fired into an open goal and left the Reds and their magnificent fans devastated.