Tyrone Barnett and Adam Thompson had given the Shrimpers a two-goal lead but goals by Nicky Ajose and Jon Obika just before halftime meant that the game was all square at the break. Further goals by Obika in the 78th minute and a solo effort in the 90th minute by Ajose sealed the win for Town.
Swindon Town included Michael Smith on the bench after returning from his loan spell at Barnsley as they lined up against Southend who included ex-Town player Michael Timlin in their starting eleven.
In the 5th minute, a pass out of defence was intercepted and Tyrone Barnett fired past Vigouroux to give Phil Brown’s Shrimpers the lead. The visitors continued to pile the pressure on Swindon and Vigouroux did well to tip a fierce shot by Dave Worrall over the crossbar for a corner.
Swindon did manage to get the ball into the penalty area in the 12th minute when Ormonde-Ottewill sent a decent cross to the edge of the 6 yard box which was cleared by the defence.
The Robins went further behind from a free kick taken by Coker who sent a looping cross to the far post for Adam Thompson to head home in the 13th minute to the delight of the 620 visiting supporters.
Jon Obika went close to opening the scoring in the 20th minute after picking the ball up on the edge of the area before firing a powerful goalbound shot which struck a defender and the ball went out for a corner.
Shrimpers keeper Bentley made an outstanding save to deny Obika from close range in the 29th minute when the Town forward sent a close range shot goalbound but the keeper instinctively pushed the ball away.
Town captain Rapha Rossi-Branco fired in a powerful shot from 30 yards which Robert managed to deflect but the visiting keeper took the ball easily.
The Robins got a foothold back in the game in the 42nd minute after Obika’s initial shot had been parried by Bentley only for Nicky Ajose to pounce and fire home from close range for his 11th goal of the season.
Town equalised in the one minute of added time when Jon Obika flicked home from close range from a throw in for his 7th goal of the season.
The second half started with heavy rain lashing down and Town made a bright start buoyed by their strong finish to the half and earned a corner in the 48th minute which led to Rossi Branco firing over.
Town continued to push forward and a decent cross by Barry was tipped away by the keeper only for Ormonde-Ottewill to fire over.
The visiting 'keeper Bentley needed treatment after taking a knock but was able to continue and he eventually made an outstanding save from a goalbound shot by Fabien Robert.
Ormonde-Ottewill went close to scoring after a surging run into the penalty area saw his shot strike a defender and out for a corner and that eventually led to Turnbull heading wide.
Town continued to push forward in search of the third goal and they were rewarded in the 78th minute after Jon Obika picked the ball up in midfield and kept powering forward into the penalty area before firing to the left of Bentley to put the Robins ahead for the first time in the match.
The goal lifted the atmosphere around the County Ground and the Robins responded with more attacking intent including Rodgers who sent a curling shot just wide.
Town’s remarkable comeback was completed on the stroke of full time when Nicky Ajose picked the ball up on the halfway line and shrugged off an attempted trip by Will Atkinson before advancing into the penalty area and firing past Bentley for Town’s fourth goal of the match.
Sponsors' Man of the Match Jon Obika was replaced deep in added time by Jermaine Hylton and the two-goal scorer left the pitch to great applause.
The Town fans gave their side a great ovation after witnessing the comeback from two goals down and the Robins now move into 16th place on 31 points in League One.