Grimsby Town's relegation to the National League was confirmed as they were beaten despite a brave performance against Exeter City at St James Park.
The Mariners went into the game knowing a defeat would almost certainly to bring their League Two survival hopes to an end and they fell behind when Luke Waterfall deflected a cross into his own net just after the half-hour.
But Town, as they have done so often in recent weeks, refused to give in and they turned the game around in their favour through a Lenell John-Lewis penalty and a second-half strike by Jay Matete.
There was another twist to come though as Matete was sent off just two minutes after putting the visitors ahead and although the 10 men valiantly tried to hold out, their resistance was broken with eight minutes to go as substitute Alex Fisher equalised.
A draw would have kept Town's mathematical chances of avoiding the drop alive after a heavy defeat for relegation rivals Scunthorpe United but the final blow was struck when Ryan Bowman's 89th minute header made it 3-2 to Exeter.
Grimsby manager Paul Hurst named an unchanged starting XI for the long trip to Devon following Saturday's excellent away victory at Oldham Athletic.
James McKeown began in goal as Elliott Hewitt, Waterfall and Rollin Menayese formed a centre-back trio. Harry Clifton and Evan Khouri were again asked to take on wing-back roles, while Matete, Giles Coke and Luke Spokes made up the midfield and Matt Green partnered John-Lewis in attack.
Sam Habergham made a return to the bench, where he was joined by Jake Eastwood, Sean Scannell, Julien Lamy, Luis Adlard and Ira Jackson Jr.
Exeter boss Matt Taylor made five changes to his starting line-up after they registered a third consecutive goalless draw in the weekend's home clash with Newport County.
They were also desperate for all three points to keep their chances of reaching the play-offs alive.
Town had the first opportunity to create danger with a Hewitt long throw from the left on three minutes but the ball was cleared by the hosts.
The first corner came five minutes later after a good spell of Mariners pressure which led to a cross from Clifton being headed behind. The ball from the flag was headed clear by Randell Williams.
Coke hit a low shot from 20 yards which went through to home keeper Jokull Andresson, before a run by Williams was brought to a halt by Menayese at the other end.
A half-volley by Exeter captain Jake Taylor was blocked and Town launched a counter-attack but after Green's cross went through to Clifton on the opposite right flank, the visitors were unable to keep the pressure up.
A low cross from Williams was cleared by Hewitt, then McKeown had to tip a header from striker Ben Seymour over the bar as the hosts continued to come into the game at the 20-minute mark.
Exeter won another corner after a cross from Josh Key eventually broke for Robbie Willmott and his cross-shot was blocked by McKeown. The delivery from the flag was dealt with by the Town defence.
Willmott fired over the bar from inside the penalty area after being found by Archie Collins, then a cross by Lewis Page failed to pick out a man in red and white.
After a promising start by the Mariners, it was Exeter who were now doing most of the attacking and they took the lead three minutes after the half-hour. Williams got down the right and sent over a low cross which was diverted into the net by WATERFALL for an own-goal.
Town's response to going behind was positive and a cross from Khouri on the left found John-Lewis, who did well to get his flicked header on target but saw it caught by Andresson.
But soon afterwards, the Mariners were given a route back into the game when Clifton was brought down inside the box by Lewis Page and the referee pointed to the penalty spot. JOHN-LEWIS stepped up to calmly send Andresson the wrong way from 12 yards and make it 1-1.
Matete was spoken to by the referee after a foul inside his own half but the hosts were unable to make the free kick count and seconds later, Green beat the offside trap at the other end but could not beat the keeper, who made a good save when the striker shot from 20 yards.
One added minute was played at the end of the half and there was time for one more Town attack as Clifton ran into space on the right after being found by Matete but he was unable to test Andresson and the scores remained level at the break.
No changes were made before the restart and the first chance of the second half went to the Mariners, with Spokes firing at Andresson from the edge of the box four minutes in.
A foul by Clifton gave the home side a free kick in a dangerous position near the left edge of the penalty area but the delivery from it was headed clear.
A slip by Hewitt soon afterwards led to a cross coming in from the Exeter left but Seymour's header was blocked and home appeals for a handball were waved away by the referee.
Exeter continued to attack and a run by Williams was stopped by Matete at the expense of a corner, although the ball from the flag was cleared.
At the other end, a Hewitt long throw was flicked into a dangerous area and put behind for a Town corner. And from it, the Mariners completed the turnaround and took the lead for the first time in the game. The ball from the flag was played short by Hewitt and after it was passed again to MATETE in space, his shot from 20 yards deflected off Pierce Sweeney and went past Andresson.
But two minutes after scoring the goal, Matete's night took a turn for the worst when he was shown a straight red card ater catching Collins on the chest with a high boot, forcing Town to play the final 30 minutes with just 10 men.
Exeter had made their first change straight after the Town goal as Matt Jay replaced Nigel Atangana and they went on to add a triple substitution on 64 minutes in a bid to turn the game back around in their favour, with Fisher, Alex Hartridge and Bowman sent on in place of Willmott, Seymour and Page.
An overhit cross from Williams was claimed by McKeown ahead of Bowman, then Collins sliced an effort from the edge of the box which took a deflection on its way out for a goal kick.
Habergham replaced Green in Town's first change, before a cross from Joshua Key on the home right was put behind for a corner, whih eventually led to an offside after Exeter kept possession.
Jack Sparkes came on for Tom Parkes in the home side's fifth and final substitution with 18 minutes to go, with their play-off hopes now appearing to be fading at 2-1 down.
Pierce Sweeney sent a dipping shot just over the bar on 75 minutes, before a foul on Khouri gave Town a rare chance to attack with a free kick on the left. Habergham's ball was met by Waterfall at the far post but his header back across goal was cleared.
Collins was booked for pulling Coke back near the halfway line but it was Exeter who were pushing forward in search of a way back into the game and a header by Bowman was deflected away for a corner before another close-range header dropped wide for a goal kick.
A Fisher header from Sweeney's cross was then tipped over the bar by McKeown for another corner on 82 minutes and this time, the hosts finally made their pressure tell as the ball dropped for FISHER and he found the net. McKeown led the protests as he believed he had been fouled but the goal stood and suddenly, Town had it all to do again.
Exeter pushed forward again straight away and they were almost ahead when a good cross from Sweeney on the left was met by Fisher but this time, he missed the target from eight yards.
It was now attack versus defence as the hosts looked for a third goal which would reinvigorate their promotion push and at the same time, relegate the Mariners.
And the 10 men had their hearts broken with a minute to go as a cross from the left was met by BOWMAN, who powered a free header into the net to make it 3-2.
The Mariners were given six added minutes to find a miracle and keep their survival hopes going and they won a corner in the first of them, although Spokes could not get a shot in when the ball broke to him at the edge of the box.
Scannell and Jackson were sent on in place of Spokes and Waterfall and Town pushed forward but they were unable to find a third goal to rescue a point and as a result, found their hopes of staying in League Two at a sad end with two games left to play.
The Mariners are next in action on Saturday, when they face Port Vale in their final home game of the season.
24 Jökull Andrésson
30 Joshua Key
20 Lewis Page
26 Pierce Sweeney
15 Tom Parkes
10 Archie Collins
11 Randell Williams
8 Jake Taylor (C)
4 Nigel Atangana
16 Robbie Willmott
9 Ben Seymour
23 Jon Maxted
2 Jake Caprice
34 Alex Hartridge
3 Jack Sparkes
17 Matt Jay
12 Ryan Bowman
18 Alex Fisher
1 James McKeown
26 Rollin Menayese
6 Luke Waterfall
22 Elliott Hewitt
15 Harry Clifton
31 Evan Khouri
20 Jay Matete
14 Luke Spokes
8 Giles Coke
7 Matt Green
21 Lenell John-Lewis (C)
44 Jake Eastwood
36 Sam Habergham
11 Sean Scannell
33 Luis Adlard
16 Ira Jackson Jr
42 Julien Lamy
Referee: David Rock
Next Up: Port Vale (H)