It was a hugely disappointing day for the Hoops fans who travelled to Hampden including a large Donegal contingent.
It just wasn’t Celticis day.
Celtic’s Gary Hooper, Anthony Stokes and Scott Brown and Killie’s Dean Shiels and Paul Heffernan all had efforts saved in a frenetic first half.
Killie keeper Cammy Bell was the man of the match pulling off incredible save after incredible save.
Bell denied Stokes and Victor Wanyama after the break.
Dieter van Tornhout headed Kilmarnock ahead six minutes from the end and Celtic could not find a leveller, with Stokes booked for diving when most fans thought it should have been a penalty.
Having lost in the final of this competition on six previous occasions, Killie were also trying to win their first trophy since 1997’s Scottish Cup triumph.
“You have to believe to achieve and we worked hard on getting the boys to believe,” Killie manager Kenny Shiels told BBC Scotland after the 1-0 win over Celtic at Hampden.
“Celtic are a young team and there is always that strain on them to succeed, so we talked up their Treble chances.
“I knew it would be difficult for them if we kept the ball because Celtic were the team under pressure.”
Kilmarnock goalkeeper Cammy Bell several fine saves and substitute Dieter Van Tornhout, celebrating his birthday, won it for the underdogs with a header on 84 minutes.
“Celtic are a fantastic team and they will go on to to be very successful,” added Shiels.
“But they were gone in the last 10 minutes.”
Neil Lennon complained about the penalty claim, but said his hurt at losing was put into perspective by a suspected heart attack suffered by Killie’ player Liam Kelly’s dad at the game.
“My sympathies go to [Liam] and his family,” added Lennon. “All my thoughts go with the family.
“It makes my pain pale into insignificance to what he’s feeling.”
Congratulations to Kilmarnock.