Strikers Roman Pavlyuchenko and Jermain Defoe scored deep into extra-time in Burnley on Wednesday to break Burnley hearts and ensure holders Tottenham Hotspur will face Manchester United in the League Cup final.
With under three minutes of extra-time left at Turf Moor, the second-tier Championship side were on course to go through to a March 1 meeting at Wembley with world champions United on the away goals rule.
At that stage the tie was all square at 4-4 on aggregate, with the Clarets 3-0 ahead in the second leg courtesy of goals from Robbie Blake, Chris McCann and Jay Rodridguez.
However, Pavlyuchenko edged Spurs in front overall before Defoe's 120th minute effort made sure Tottenham manager Harry Redknapp, who won the FA Cup with Portsmouth last season, would be heading back to Wembley after a dramatic 6-4 aggregate success.
Burnley, who'd already knocked Premier League sides Fulham, Chelsea and Arsenal out of the League Cup this season, were 100-1 rank outsiders to go through before the second-leg kicked-off.
But on a windswept and rain-drenched evening in the north-west, Burnley, on the fringes of the race for promotion to the Premier League, made a mockery of those odds.
Ben Alnwick made his Spurs debut as first-choice keeper Heurelho Gomes was missing for the top-flight strugglers through injury along with Ledley King, Vedran Corluka and Aaron Lennon.
Meanwhile Pavyluchenko, who has now scored in every round of the competition, and Gareth Bale dropped to the bench.
The Clarets were themselves weakened by being without suspended captain Steven Caldwell and cup-tied striker Steve Thompson, Wade Elliott and Blake respectively filling in.
Spurs almost scored first when Jonathan Woodgate one of just two survivors along with Didier Zakora from the Spurs side that beat Chelsea 2-1 in last year's final - headed over from David Bentley's corner.
But instead it was Burnley who broke the second leg deadlock.
They were awarded a free-kick after Woodgate's foul on Joey Gudjohnsen and from fully 25 yards out Blake beat Alnwick at the keeper's near post with a superb curling effort.
Clarets manager Owen Coyle had said beforehand his side would need "to scale Everest and beyond" to reach the final but now the summit was in sight.
Midway through the second-half, Spurs had the chance to draw level in the second leg when Defoe pounced on an error by Clarke Carlisle.
But Burnley keeper Brian Jensen moved smartly off his line to deny the England striker.
Burnley continued to press forward and in the 73rd minute a cross from Blake was turned in at the far post by McCann.
Spurs advantage was erased with two minutes of normal time left, after Alnwick fumbled Blake's free-kick, substitute Rodriguez scored.
At the end of normal time, Martin Paterson's first-leg goal for Burnley - which had seemed as if it would be a mere footnote - meant the Clarets were still in the tie.
Now, however, they had a position to defend and the character of the match changed with Spurs's making the running in the first-half of extra-time.
But Burnley did not concede and were in sight of a first League Cup final appearance when Pavlyuchenko, who came on for Luka Modric midway through the second-half, scored from six yards in the 118th minute.
And moments later Defoe grabbed another goal, to make sure of an all top-flight clash with United, 4-3 aggregate winners over Derby on Tuesday.