Dundee's brave bid to beat the drop from the Clydesdale Bank Premier League was cut down by a Niall McGinn penalty as Aberdeen denied the Dark Blues the win that would have kept them in the fight for another week as they recorded a 1-1 draw.
The Dens Park outfit had slashed the 15-point deficit at the bottom of the table inherited by John Brown when he took over in February to just eight points.
Victory over the Dons would have reduced it again to five with two to play but their hopes of a remarkable escape act were ended by McGinn's second-half penalty.
Dundee had led through Jim McAlister's deflected strike on 20 minutes and looked in command when the visitors had Rory Fallon sent off after an off-the-ball clash with Declan Gallagher.
But disaster struck when Lewis Toshney brought down Peter Pawlett and McGinn made no mistake from 12 yards to send Dundee down after just one season in the top flight.
Meanwhile, Kilmarnock's clash with Hibernian at Rugby Park was abandoned after a supporter was taken to hospital after receiving medical treatment at the side of the pitch in front of the East Stand.
The incident occurred at the start of the second half with referee Kevin Clancy initially stopping the game, which was tied at 1-1, after five minutes - with the players then going down the tunnel when the seriousness of the situation became clear.
Medical staff from Killie and Hibs were in attendance before an ambulance drove pitchside 10 minutes later with the supporter being taken away before the club confirmed the game had been abandoned due to an off-pitch incident.
Inspector Sean Mangan, the match commander, said: "A supporter was taken ill in the East Stand, possibly a Kilmarnock fan. Ambulance staff and club doctors have been assisting with that male, he has now gone off to the hospital in the ambulance.
"It is looking like a possible suspected heart attack but of course I am not a medical professional to absolutely tell you that is the case but it is certainly serious enough that the club, in conjunction with the police and the SPL fourth official, have decided out of respect for the male and possibly his family that the match would be abandoned."