Town’s defeat and Rotherham United’s victory at Gillingham meant it was the latter dropping into League Two.
Fleetwood, Gillingham and Morecambe could all have taken the final relegation place but, with all three losing, it was the Gills joining AFC Wimbledon, Doncaster Rovers and Crewe Alexandra in the fourth tier.
Crainey admitted: “It was on a knife edge right until the end, I am not going to lie.
“I am just thankful we are staying in League One, it’s one of my most nervous days (in football) especially as a manager.
“I have got a great group of footballers and I think it is a group that can do something special in League One next season.
“I am obviously disappointed to lose the game first. We came here with a game plan I believed could win the game.
“When we went 2-1 down, I thought ‘Lads, right what have you got?’. I thought we responded well.
“Joe (Garner) pops one in and I am thinking ‘Can we go on and win the game?’. Then there was a freak goal to make it 3-2 which was a sucker punch.”
Dion Charles will never score a more bizarre goal; a blocked tackle with Callum Camps resulting in the ball looping 45 yards over Alex Cairns.
“I feel as though that sort of thing has been going against us all season,” grimaced Crainey.
“Then we got news in the dugout results were going in our favour, so it is mixed emotions.”