Aberdeen crashed into the Conference League after they were blitzed in Bucharest.
The Dons had travelled to the Romanian capital with Europa League group stage dreams.
They were left in tatters after VAR i ntervened to give Alexander Jensen a red card and to award FCSB a first half penalty.
The home side netted through captain Darius Olaru and never looked back.
Jimmy Thelin made changes at the interval but they didn’t work and FCSB ran over the top of the Scottish Cup winners.
They put Aberdeen to the sword thanks to another from Adrian Sut and a second from Olaru in the National Arena.
This was an opportunity missed. FCSB are no great shakes but still ran out worthy winners.
It was another nightmare night in what has been a week full of them for the majority