Scott Neilson scored the decisive goal to send Reds into League 1 as they beat Accrington 1-0 at the Crown Ground.
Neilson, who was recalled to the side by Craig Brewster along with four others, scored midway through the second half to seal back-to-back promotions.
The 631 Reds fans who travelled were in brilliant voice and the party began in style when Darren Deadman blew the final whistle after four minutes of stoppage time.
With Southend winning, it meant Reds had to win, and they did just that despite a nervy end to the game to join Swindon and Shrewsbury in League 1.
Brewster made five changes to the side that lost a week ago against Hereford. Scott Shearer replaced Michel Kuipers in goal, while David Hunt and Warren Cummings came in at right and left back respectively.
Kyle McFadzean dropped into the heart of defence alongside Claude Davis with Josh Simpson moving into the centre of midfield. Neilson came in for Scott Davies at right back while John Akinde started in attack alongside Gary Alexander.
Reds knew exactly what they had to do, and after a lively start by the hosts Brewster's side created their first opening as Akinde went close with a 20-yard drive.
But the home side were looking confident, and almost went ahead as Padraig Amond latched onto a ball over the top of the defence, only for Shearer to pull off an excellent save with his leg.
From the resulting corner, the recalled 'keeper was back in the action, this time expertly keeping out Michael Liddle's header.
Those chances seemed to wake Reds up after a somewhat sluggish start and Alexander was a whisker away from connecting with Akinde's cross.
Simpson then saw his effort blocked away by Peter Murphy before Aristote Nsiala made a vital interception from Neilson's cross.
Wih just over 30 minutes on the clock, Alexander had his first real sighting of goal from McFadzean's cross, but he couldn't quite get the power behind the shot.
Accrington were threatening from set pieces and were almost ahead from a corner with five minutes of the half remaining.
Jamie Devitt's delivery found Amond who saw his header beat Shearer but not Hunt, as the defender cleared off the line.
As first half stoppage time began, Reds had their best chance of the game. Alexander held the ball up for Simpson who fed Neilson, but the midfielder fluffed his lines when one-on-one with Ian Dunbavin.
Reds started the second half brightly, and Alexander again should have done better when Hunt's deep cross found him unmarked, but he couldn't direct his header on target.
Minutes later, Reds had another chance as Neilson's low cross found Akinde, but the striker was unable to keep his effort down.
It was then Davis' turn to go close, as he met Cummings' free kick, but Dunbavin was on hand to parry away with Akinde charging in.
Reds were threatening every time from set pieces, and were within a whisker of going ahead when McFadzean met Hunt's long throw. But the looping header flicked over off the crossbar.
It was all Reds pressure and again, they were denied by the crossbar as this time Dunbavin tipped Akinde's powerful drive onto the woodwork.
From the resulting corner, Reds were again unlucky as Craig Lindfield cleared McFadzean's header away on the line.
With 66 minutes gone, the pressure finally paid off. Cummings played the ball over the top for Neilson, who turned smartly before drilling the ball past Dunbavin into the bottom corner.
Brewster switched to 4-5-1 with Akinde moving to the left hoping to shore things up defensively as Accrington pressed and it paid off.
For all the home side's pressure, it was Reds who had the better chances with Akinde and Alexander going close.
One goal was enough though for Reds as they sealed a second successive promotion to ensure the likes of Portsmouth, Coventry and Doncaster will visit the Broadfield next season.