Match ends, Dundee 2, Dundee United 1.
Dundee United's worst nightmares were realised when their city rivals beat them - and relegated them - at a raucous Dens Park.
Mixu Paatelainen's team gave themselves a chance when Edward Ofere side-footed John Rankin's pass into the net.
Dundee came storming back, though, with an equaliser from Kane Hemmings after Kosta Gadzhalov's header.
That alone was enough to send United down, but Dundee added a second when Craig Wighton found the far corner.
Dens Park rejoiced in their rivals' misery, lapping up the victory and all that it meant, all the pain and misery dumped on top of a beleaguered, and emotional, United support.
Some of those United fans exited in silence, some left in tears, others fired some volleys at their chairman, Stephen Thompson, before drifting into the night. What lies ahead, nobody knows. But this club is broken right now.
It was an odd evening. For fully 55 minutes, until Ofere silenced the home crowd, United never looked capable of doing what needed to be done to stave off doomsday. They just weren't at the races. They were again hesitant and nervy at the back and loose in possession, continually inviting trouble on themselves with their careless use of the ball.
Their old foes were up for it, as if there was any doubt about it. It was Paul Hartley's team that carried a goal-scoring threat, principally through the inventive Greg Stewart. The nominee for PFA Scotland's player of the year was clever all night. His fellow nominee, Hemmings, was also a regular source of concern.
The best chance of the opening half - Dundee were dominant but just not accurate enough to pepper United's goal - fell to Hemmings after Paul Dixon was robbed in possession and Dundee scampered downfield.
However, despite being so consistent for so much of this season, he ballooned his shot over.
Dundee were denied a big claim for a penalty early in the second half when Darren O'Dea went tumbling in the box, but even there wasn't a whole lot of Dundee anger about the decision. The notion that United would soon score and turn the narrative on its head seemed potty at the time. That's what happened, though.
United, in really their first piece of constructive football, broke down the left-hand side and when Rankin slid in a low cross, Ofere was there all on his lonesome to guide it past goalkeeper Scott Bain.
In those minutes after the goal, United came alive. Nick Ross had to kick a Mark Durnan header off the line, then Kyle Knoyle put Ofere through one-on-one with Bain. It was a highly dramatic and hugely significant moment. Had Ofere scored then United surely had the game won. He didn't; Bain denied him.
And how telling that save was to prove. Within a few minutes, Hemmings got himself into the middle of a goalmouth scramble after Gadzhalov connected with a Gary Harkins corner and put away an equaliser that sent Dens Park into raptures.
Even then, with tempers frayed, United could have scored again; Chris Erskine rifling a shot on goal that Bain tipped over. Down the other end, Dundee pressed hard and could have scored themselves, Eiji Kawashima saving twice.
Eventually they did, the wonderful Stewart placing a free-kick into the path of Wighton, who finished with aplomb.
The clock ticked on agonisingly for United. Then time ran out, in every sense.
Hemmings and Wighton landed the knockout blows that sent them plummeting through the trap door and into the Championship next season, but the wound that Dundee inflicted on United was nothing compared to the wound that United inflicted on themselves in the many months that went before.
From the boardroom to the pitch - not good enough. Nowhere near.
- 1BainBooked at 80mins
- 21O'DeaBooked at 86mins
- 18McGowanSubstituted forEtxabegurenat 17'minutes
- 7StewartBooked at 85mins
- 22Rodríguez Pérez Reverte
- 1KawashimaBooked at 84mins
- 2DillonBooked at 90mins
- 3DixonBooked at 4mins
- 22FraserSubstituted forDowat 63'minutes
- 6PatonBooked at 85mins
- 20SpittalSubstituted forMckayat 87'minutes
- 15MurraySubstituted forErskineat 73'minutes
- William Collum
- Shots on Target
Second Half ends, Dundee 2, Dundee United 1.
Goal! Dundee 2, Dundee United 1. Craig Wighton (Dundee) right footed shot from the centre of the box to the bottom left corner. Assisted by Greg Stewart with a cross following a set piece situation.
Sean Dillon (Dundee United) is shown the yellow card for a bad foul.
Kane Hemmings (Dundee) wins a free kick in the defensive half.
Foul by Sean Dillon (Dundee United).
Greg Stewart (Dundee) wins a free kick in the attacking half.
Foul by Paul Dixon (Dundee United).
Foul by Kane Hemmings (Dundee).
Sean Dillon (Dundee United) wins a free kick in the attacking half.
Attempt missed. Chris Erskine (Dundee United) right footed shot from the right side of the box is close, but misses the top right corner.
Corner, Dundee. Conceded by Eiji Kawashima.
Substitution, Dundee United. Billy McKay replaces Blair Spittal.
Darren O'Dea (Dundee) is shown the yellow card.
Paul Paton (Dundee United) is shown the yellow card for a bad foul.
Craig Wighton (Dundee) wins a free kick in the defensive half.
Foul by Paul Paton (Dundee United).
Greg Stewart (Dundee) is shown the yellow card for a bad foul.
Foul by Greg Stewart (Dundee).
Paul Dixon (Dundee United) wins a free kick on the right wing.