Rangers boss Mark Warburton says referee John Beaton cost his side a point after awarding the free-kick which led to Aberdeen's dramatic Pittodrie winner.
James Tavernier was harshly penalised for a foul on Johnny Hayes and the match official's mistake proved decisive as James Maddison whipped home a stunning stoppage-time set-piece to seal a 2-1 victory.
It is another dose of disappointment for Gers, who have managed just two wins from their seven Ladbrokes Premiership fixtures, leaving them floundering in the bottom half of the table.
Warburton tried to play it diplomatically after the match but could not hide his annoyance at Beaton's big call.
He said: "I thought the referee handled a difficult game very well. He did a really good job up to that point, but to give that one there is frustrating beyond belief.
"I will be careful what I say about the free-kick. Everyone saw the ball move. The fourth official on the sidelines saw the ball move and made a comment. And yet a free-kick is given.
"You have got to be, I think, 100 per cent sure in these type of games, in those areas of the park.
"It was an outstanding tackle. Late in the game, when your players are fatigued, I thought Tav made an excellent tackle there. I don't think their player moaned about it and it is a huge decision to give."
Rangers found themselves facing a wall of noise as they made their first visit to the Granite City in four and a half years.
Extra police had to be called in to separate the rival fans as temperatures threatened to boil over during the match.
The Light Blues settled well and dominated the first period but Aberdeen struck first when Hayes sped past the static Light Blues defence to slot home just 22 seconds into the second half.
Gers got a lifeline when Hayes tripped Lee Wallace in the box, with Andy Halliday squaring the match on 77 minutes, but then Beaton handed on-loan Norwich playmaker Maddison his chance to shine.
"There's no doubting that the moment of real quality should be applauded," said his boss Derek McInnes.
"It was a game that had a lot in it, a lot of challenges, a lot of bookings, a lot of frantic play, a lot of measured play, especially from Rangers I have to say.
"But in the dying seconds of the game the stage was set for the young man to step up and score. That goal was as good as any goal you'll see. It was terrific.
"It says everything about him. Terrific composure. When everybody is excitable around about him and the clock's being run down, to produce that bit of quality that's why we deserved to win the game. No question."
Warburton was convinced his side merited more but believes they are making progress.
He said: "We dominated the ball first half completely but we went in at half-time frustrated it finished 0-0.
"We gave away a schoolboy goal and for three or four minutes we looked a bit rocky. We lost our composure then got the ball down, then played. We got our rewards via the penalty and I thought there was (only) one team in it.
"I said to (assistant) Davie Weir we'd be frustrated to only get a point here when we have come and delivered a really good performance. I am never happy to drop a point, never mind three.
"But we moved to the next level today as a team and we are getting better.
"The boys are settling in and we were delighted with long periods of that game where we completely dominated."
