Aberdeen fought back thanks to goals from Bruce Anderson and Lewis Ferguson in the second-half at Rugby Park.
Aberdeen made one change to the side that defeated Hamilton midweek, Dominic Ball came into the starting line-up with Scott Wright dropping to the bench. Stephen Gleeson was injured in the pre-match warm-up, and youngster Dean Campbell took his place on the bench.
Andy Considine was also on the bench after missing the game against Hamilton with a neck injury after he was stretchered off during the 1-0 Betfred semi-final win against The Rangers.
Kilmarnock dominated for most of the match and went ahead through a Fat Boy penalty, Kilmarnock looked to be in control of the game – the match in most part a hard watch for the travelling Dons who made the journey down.
However, those hardy fans had reasons to be cheerful, barely minutes on the pitch sub Bruce Anderson levelled the score – our first shot on target, the young Don racing in front of his marker to direct it beyond keeper Jamie MacDonald.
Then to wrap the game up for the Dons, Lewis Ferguson was on target after hitting home a superb 25-yard free kick to secure the victory.
Derek McInnes said: “Killie played with far more intent, more aggression, the penalty epitomised how we were – Shay’s Logan challenge was limp, half hearted.
“The only one for me who had a 90-minute performance in him was young Lewis [Ferguson].
“But everybody in the second half gave an Aberdeen performance. Not brilliant in terms of quality, but there was far more intent.”
The win puts the Dons up to seventh in the league and only three points behind The Rangers in third.
It seals a big week for Aberdeen and Derek McInnes, after beating The Rangers in the League Cup Semi-Final and two league wins.