Match ends, Cheltenham Town 0, Northampton Town 3.
Northampton Town produced a pulsating fightback to overturn a two-goal deficit from the first leg and stun Cheltenham Town to reach the League Two play-off final.
Seemingly with it all to do after Thursday's 2-0 home defeat, Keith Curle's Cobblers scored three times without reply at the Jonny-Rocks Stadium to clinch a meeting with Exeter City in the behind-closed-doors final at Wembley on 29 June.
Cheltenham's solid-looking first-leg advantage was halved within nine minutes as Northampton were rewarded for a bright start through Vadaine Oliver's clinical downward header.
On-loan West Bromwich Albion forward Callum Morton then scored twice in the second half to complete a deserved turnaround for the spirited visitors, with the winner coming 13 minutes from time as he capitalised on a disastrous mix-up in the hosts' defence.
Monday's dramatic comeback kept alive Northampton's hopes of returning to League One after just a two-year absence, while Cheltenham now face a 12th consecutive season below the third tier.
Morton makes most of rare defensive lapses
Morton was mobbed by his team-mates after netting the winner, with any thoughts of socially distanced celebrations momentarily forgotten by the jubilant Northampton players, who fully merited their victory.
But the decisive goal came in fortunate circumstances after an uncharacteristic moment of calamity at the back from the hosts, who had only conceded 27 league goals all season before Monday's drama.
Only Premier League leaders Liverpool could boast a statistically meaner defence than the Robins in England's top four leagues this term, but it was hard to fathom that as Northampton snatched their third of the night.
Cheltenham defender William Boyle attempted to allow a stray ball to roll back to his goalkeeper Owen Evans - who had saved a penalty in a brilliant first-leg display between the sticks - but the pair misjudged the situation completely.
The on-rushing Michael Harriman duly pounced and his shot struck the base of the post with Morton able to slot in on the rebound.
That came after the 20-year-old had added to Oliver's first-half opener, as more slack Cheltenham defending saw the ball hit Morton's head after Charlie Goode's initial header bounced around the box.
After Morton's second, Alfie May twice went close to levelling the tie on aggregate in the closing moments, but Cheltenham failed to force extra time.
It was a frustrating end to an otherwise excellent first full campaign in charge for former Northern Ireland, Burnley and Cheltenham defender Michael Duff, who took over as manager in September 2018 when the Robins were 18th in the table.
Meanwhile, Curle's side had lost seven of their previous nine games in all competitions but are now just one win away from promotion.
With their fightback, they became the first team in the English Football League to lose the first leg of a play-off tie by two or more goals and then progress to the final since Yeovil Town fought back against Nottingham Forest in League One in 2007.
Cheltenham manager Michael Duff told BBC Radio Gloucestershire: "We didn't turn up. We got beaten up. We didn't do the basics of the game, which we normally do well. We didn't do any part of it very well.
"It's the first time we've been beaten up this season. Maybe a few froze on the night.
"I'm obviously devastated with what's just gone on, but ultimately there's not a person in this town who wouldn't have taken this season [at the start of the season].
"The hard thing now will be trying to replicate it, because people will expect you to finish [up there] again. The difficult part will be managing expectation, because you normally finish where your money tells you.
"We've had a very good season, the best season the club's had in a long time, but it's now about not resting on our laurels and asking 'How do we do it again?' There are some big clubs coming down."
Northampton boss Keith Curle told BBC Radio Northampton: "I'm very proud. Not just of the performance, but a lot of work has gone on behind the scenes.
"I'm obviously immensely proud of the players and coaching staff, but the staff at the club, the medical staff, the chief executive, the chairman, the secretary - they've all played their part in giving us a platform. Everything has been done correctly.
"Our plan was to get the first goal knowing that can have an impact.
"A 2-0 lead is a difficult lead, especially in a second leg at home. It's a mental challenge for the players.
"We know what it feels like when you're 2-0 up and the opposition scores. We wanted Cheltenham to have that feeling because we thought we could impose ourselves."
- 5RaglanSubstituted forNicholsat 81'minutes
- 11BroomSubstituted forAddaiat 62'minutes
- 21Doyle-HayesSubstituted forInceat 62'minutes
- 27SmithSubstituted forReidat 45'minutes
- 4McCormackSubstituted forOlayinkaat 71'minutesBooked at 79mins
- 10AdamsSubstituted forMartinat 86'minutes
- 39MortonBooked at 90mins
- 19OliverSubstituted forSmithat 84'minutes
- Leigh Doughty
- Shots on Target
Second Half ends, Cheltenham Town 0, Northampton Town 3.
Attempt saved. William Boyle (Cheltenham Town) with an attempt from the centre of the box is saved in the bottom right corner. Assisted by Ben Tozer.
Foul by Chris Hussey (Cheltenham Town).
Callum Morton (Northampton Town) wins a free kick in the defensive half.
Callum Morton (Northampton Town) is shown the yellow card.
Foul by Sean Long (Cheltenham Town).
James Olayinka (Northampton Town) wins a free kick on the left wing.
Attempt missed. Callum Morton (Northampton Town) right footed shot from the centre of the box is too high. Assisted by Sam Hoskins.
Hand ball by Alfie May (Cheltenham Town).
Attempt missed. Alfie May (Cheltenham Town) right footed shot from the left side of the box is just a bit too high.
William Boyle (Cheltenham Town) wins a free kick in the defensive half.
Foul by Harry Smith (Northampton Town).
Attempt missed. Alfie May (Cheltenham Town) left footed shot from a difficult angle on the left is just a bit too high. Assisted by Tom Nichols.
Substitution, Northampton Town. Joe Martin replaces Nicky Adams.
Attempt blocked. Rohan Ince (Cheltenham Town) right footed shot from outside the box is blocked. Assisted by Tom Nichols.
Substitution, Northampton Town. Harry Smith replaces Vadaine Oliver.
Attempt saved. Callum Morton (Northampton Town) left footed shot from the left side of the box is saved in the top centre of the goal. Assisted by Sam Hoskins.
Corner, Cheltenham Town. Conceded by Scott Wharton.
Substitution, Cheltenham Town. Tom Nichols replaces Charlie Raglan.
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