Barry Corr returned from a 17-month injury lay-off to help Southend come from behind and beat Exeter.
Scot Bennett finished off a sweeping move to put the visitors ahead just after the break.
Jamie Cureton fired straight at Daniel Bentley when one-on-one, and, with things looking bleak for the Shrimpers, boss Paul Sturrock threw on Corr.
And he powered home a header for 1-1, before Freddy Eastwood nodded in a late winner at the far post.
VIEW FROM THE DRESSING ROOM
Southend United manager Paul Sturrock told BBC Essex:
"Exeter got in the lead and obviously fans get disgruntled and players get disheartened, so it needed a couple of substitutions.
"Freddy [Eastwood] went on and got better as the game went on and obviously Barry Corr, with 17 months of pent up frustration, scored a header that went in like a bullet.
"He is nowhere near fit, but for that 20-minute cameo role he's ideal.
"You've got to give him credit where credit is due. He's hurting all over but he's prepared to die for the cause."
Exeter City manager Paul Tisdale told BBC Radio Devon:
"We're very irritated that we've lost late. It's frustrating as we've played so well today and we were every bit as good as we have been on the road in the previous three games.
"We were very controlled, very organised, very sensible and defended really well. We controlled the game and at 70 minutes I thought we had just as much chance, if not more, of scoring a second as they had of scoring an equaliser.
"I'm not going to beat the players with it, they need to beat themselves about what they could have done at the end, that's their responsibility."
Live Text Commentary
Full Time The referee signals the end of the game.90:00 +2:45 Booking
Booking Matt Oakley is shown a yellow card.90:00 +2:32
Free kick awarded for an unfair challenge on Barry Corr by Matt Oakley. Kevan Hurst restarts play with the free kick.90:00 +1:15
Arron Davies has an effort at goal from just inside the box that misses to the right of the target.90:00 +0:46
Britt Assombalonga is ruled offside. Direct free kick taken by Danny Coles.89:45 Substitution
Substitution Steve Tully joins the action as a substitute, replacing Tommy Doherty.89:26
Arron Davies takes a shot and went wide right of the net.87:11
Assist by Chris Barker.87:11 Goal scored
Goal! - Freddy Eastwood - Southend 2 - 1 Exeter Freddy Eastwood grabs a headed goal from close in. Southend 2-1 Exeter.87:06
Chris Barker crosses the ball,86:24
Long range shot by Ryan Leonard goes wide right of the target.84:05
The ball is crossed by Kevan Hurst, Headed effort from deep inside the area by Britt Assombalonga misses to the left of the goal.81:49
Britt Assombalonga has an effort at goal from the edge of the box that misses to the right of the target.80:27 Substitution
Substitution Tom Nichols joins the action as a substitute, replacing Jimmy Keohane.78:49
Corner taken right-footed by Arron Davies.77:40
Sean Clohessy provided the assist for the goal.77:40 Goal scored
Goal! - Barry Corr - Southend 1 - 1 Exeter Barry Corr finds the net with a headed goal from inside the six-yard box. Southend 1-1 Exeter.77:26
Kevan Hurst decides to take a short corner, Sean Clohessy delivers the ball,76:53
Britt Assombalonga takes a shot. Artur Krysiak makes a save.76:38
Kevan Hurst takes a shot.
Luke Prosser produces a left-footed shot from just outside the box that goes wide left of the target.74:45
Corner taken by Kevan Hurst from the right by-line, clearance made by Scot Bennett.72:45
Freddy Eastwood has a shot on goal from outside the area which misses left.71:17 Substitution
Substitution John Spicer goes off and Barry Corr comes on.70:39
A cross is delivered by John O'Flynn, Effort from the edge of the area by Jimmy Keohane goes wide of the right-hand upright.68:58
Britt Assombalonga concedes a free kick for a foul on Tommy Doherty. Free kick taken by Danny Coles.65:47
Arron Davies decides to take a short corner.64:58
Corner taken by Arron Davies from the right by-line to the near post, Scot Bennett takes a shot. Chris Barker gets a block in.60:43 Substitution
Substitution (Exeter) makes a substitution, with John O'Flynn coming on for Jamie Cureton.59:39
Corner taken right-footed by Kevan Hurst, clearance by Scot Bennett.56:47 Substitution
Substitution Ryan Leonard comes on in place of David Martin.56:47 Substitution
Substitution (Southend) makes a substitution, with Freddy Eastwood coming on for Elliot Benyon.56:25
Jamie Cureton takes a shot. Daniel Bentley makes a save.54:55
The referee blows for offside. Artur Krysiak takes the direct free kick.54:06
Headed effort from inside the penalty area by Britt Assombalonga misses to the right of the target.52:12
Unfair challenge on Danny Coles by Elliot Benyon results in a free kick. Craig Woodman takes the direct free kick.50:31
Assist by Pat Baldwin.50:31 Goal scored
Goal! - Scot Bennett - Southend 0 - 1 Exeter Goal scored by Scot Bennett from deep inside the penalty area to the bottom right corner of the goal. Southend 0-1 Exeter.49:47
Outswinging corner taken right-footed by Arron Davies from the right by-line to the near post, Michael Timlin makes a clearance.47:59
The ball is swung over by Arron Davies, Ryan Cresswell makes a clearance.46:40
The ball is swung over by Kevan Hurst, Elliot Benyon gives away a free kick for an unfair challenge on Pat Baldwin. Artur Krysiak restarts play with the free kick.45:44
Shot from outside the area by Britt Assombalonga misses to the left of the target.45:01
The second half begins.45:00 +2:13 Half time
Half Time The whistle is blown to end the first half.45:00 +1:56
Michael Timlin takes a shot. Kevin Amankwaah gets a block in.45:00 +1:32
A cross is delivered by Sean Clohessy, blocked by Danny Coles.45:00 +0:01
Chris Barker crosses the ball, Shot by Elliot Benyon from deep inside the penalty area misses to the right of the goal.44:11
Free kick awarded for an unfair challenge on Jimmy Keohane by Kevan Hurst. Free kick taken by Craig Woodman.40:14
Kevan Hurst produces a cross, Artur Krysiak makes a save.39:52
Kevan Hurst takes a outswinging corner from the right by-line to the near post, Craig Woodman manages to make a clearance.39:43
Chris Barker delivers the ball.38:59
Inswinging corner taken from the left by-line by Kevan Hurst, Danny Coles manages to make a clearance.38:46
Unfair challenge on Elliot Benyon by Danny Coles results in a free kick. Free kick taken by Luke Prosser.38:31
Centre by Tommy Doherty, clearance by Sean Clohessy.35:59
The ball is sent over by Sean Clohessy, save made by Britt Assombalonga.34:57
Centre by Sean Clohessy, save by Artur Krysiak.33:11
Foul by Tommy Doherty on Elliot Benyon, free kick awarded. Kevan Hurst restarts play with the free kick.30:04
Kevan Hurst gives away a free kick for an unfair challenge on Kevin Amankwaah. Direct free kick taken by Craig Woodman.27:57
Danny Coles gives away a free kick for an unfair challenge on Elliot Benyon. Kevan Hurst shoots direct from the free kick, save by Artur Krysiak.27:06
A cross is delivered by Kevan Hurst, Danny Coles makes a clearance.25:59
Centre by Sean Clohessy, Header on goal by Britt Assombalonga from inside the box goes harmlessly over the target.25:19
Jamie Cureton produces a right-footed shot from the edge of the area and misses to the left of the goal.23:38
Shot from a long way out by Ryan Cresswell goes wide of the left-hand post.22:57
Chris Barker produces a cross, clearance made by Craig Woodman.22:07
Michael Timlin fouled by Tommy Doherty, the ref awards a free kick. Ryan Cresswell takes the free kick.20:29
Britt Assombalonga delivers the ball, John Spicer takes a shot from just inside the penalty box which clears the crossbar.19:34
David Martin challenges Tommy Doherty unfairly and gives away a free kick. Artur Krysiak restarts play with the free kick.19:00
Jamie Cureton takes a shot. Save made by Daniel Bentley.18:37
Free kick awarded for a foul by Sean Clohessy on Scot Bennett. Craig Woodman takes the free kick.17:21
Pat Baldwin fouled by Michael Timlin, the ref awards a free kick. Free kick taken by Artur Krysiak.15:50
Craig Woodman concedes a free kick for a foul on Kevan Hurst. Kevan Hurst takes the free kick.14:28
Sean Clohessy sends in a cross, Pat Baldwin manages to make a clearance.11:05
Jamie Cureton has an effort at goal from the edge of the area that misses to the right of the target.9:37
Kevan Hurst takes the inswinging corner, clearance by Jimmy Keohane.7:45
Jamie Cureton takes a shot. Save by Artur Krysiak.7:04
Unfair challenge on Britt Assombalonga by Kevin Amankwaah results in a free kick. Kevan Hurst takes the free kick.5:29
Foul by Ryan Cresswell on Danny Coles, free kick awarded. Free kick taken by Artur Krysiak.4:59
Tommy Doherty gives away a free kick for an unfair challenge on Kevan Hurst. Kevan Hurst takes the direct free kick.2:37
David Martin concedes a free kick for a foul on Matt Oakley. Artur Krysiak takes the free kick.1:30
A cross is delivered by Kevin Amankwaah, save made by Daniel Bentley.0:56
The assistant referee flags for offside against Elliot Benyon. Direct free kick taken by Pat Baldwin.0:24
John Spicer gives away a free kick for an unfair challenge on Jimmy Keohane. Tommy Doherty restarts play with the free kick.0:00
The ref blows the whistle to begin the match.
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