Dundee United fought back from a goal down at Hampden to beat defending champions Aberdeen 2-1 and book a place in the QTS Scottish League Cup final.
On-loan West Brom defender Donervorn Daniels marked his Dons debut with a goal four minutes after half-time.
But Callum Morris squared the semi-final clash at the National Stadium on the hour mark before Nadir Ciftci's deft header seven minutes from time squirmed through Reds keeper Scott Brown's hands.
The defeat ends Derek McInnes' hopes of leading his Pittodrie side to back-to-back League Cup wins, while United will now take on the winner of Sunday's derby clash between Celtic and Rangers in the March 15 trophy decider.
Like McInnes, United boss Jackie McNamara also threw a debutant straight into action as former Hearts defender Ryan McGowan started a week after joining from Chinese side Shandong Luneng Taishan.
With the hype surrounding Sunday's Old Firm clash, the build-up to the meeting of the New Firm was cast into the shadows.
But for many, Saturday's semi promised a better standard of football, with high-flying Aberdeen still candidates for the Scottish Premiership title.
McNamara's side, meanwhile, can match anyone in the league on their day - as they proved when they beat Ronny Deila's leaders last month - but often lack of consistency.
However, it was the Taysiders who started the brighter. Ciftci took a quick free-kick four minutes in to find Gary Mackay-Steven galloping in behind the Dons defence.
While the Celtic-bound winger's touch took him past keeper Scott Brown, he fluffed his shot.
The Arabs came close again when Stuart Armstrong's one-two with Charlie Telfer opened up space for the playmaker to send a deflected shot onto the crossbar.
But the hoped-for display of open, attacking football failed to materialise in the opening stages as both sides scrapped it out on the rutted Hampden pitch.
Daniels' misplaced clearance let Armstrong have another go but he made amends with an instant block.
Aberdeen's best opening came seven minutes before the break as Niall McGinn burst down the left before rolling the ball across goal. Adam Rooney teed it up for the onrushing Peter Pawlett but his effort was denied when Morris threw himself at the shot.
Sean Dillon also had to be brave as David Goodwillie's follow-up effort came in but United survived.
Luck, though, evaded them just after the change of ends when Andrew Considine launched a long throw into the box for Daniels to flick on.
It did not look like the 21-year-old was going for goal but his looping header caught out hesitant keeper Radoslaw Cierzniak before bouncing into the net off the back post.
Mackay-Steven had the ball in the net seconds later as United went in search of an instant response but the offside flag was already up.
Aberdeen nearly had a second as Cierzniak flapped at another delivery, this time a Hayes corner, but Ciftci cleared Goodwillie's header from underneath his own bar.
McNamara sent on Ryan Dow after 57 minutes and within moments he won the corner that drew United level as Morris thudded home a powerful header after Mackay-Steven swung over a devilish delivery from the right.
The goalscorer had more defensive duties to do, though, as he denied Daniels a second with a point-blank range intervention.
After that sloppy first half, the action was now frantic. Rooney thought he had put his side back in front as he bulleted another header into the net from a McGinn corner, but referee Steven McLean chalked it off after spotting the striker's nudge on Calum Butcher.
Another chance went abegging for McInnes' men when Cierzniak pulled off a stunning reflex save to deny Ryan Jack, while at the other end Dow steered the ball past Brown after Mark Reynolds was short with a back pass - only to see the guilty defender make amends with a last-ditch clearance.
Goowillie then wasted another header he should have scored from eight yards out - and he would regret it.
With just seven minutes remaining Ciftci got the faintest of touches to Paul Paton's cross to direct it past Brown and clinch United's place in the final.
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