Aberdeen’s bid to win the Scottish Cup for the first time since 1990 continued due to true grit and the heroics of keeper Freddie Woodman.
The Reds were a goal down in extra-time and staring into the abyss in a game that was make or break for their season.
Facing a cup exit on the back of a four-game winless slump the pressure was intense – but the Reds refused to buckle.
This was a blood and thunder tie and they would not lie down – they dug deep to book a semi-final slot against Motherwell at Hampden on April 14.
Seasons swing on games like these and this result can provide the propulsion to get the bid to finish second in the Premiership back on track.
High pressure situations call for big players – step up on-loan Newcastle United stopper Woodman.
Who better for a high stakes shoot-out than a keeper who saved a spot-kick in a World Cup final to win the trophy?
Just nine months ago the 20-year-old saved a spot kick against Venezuela in a 1-0 final win as England secured the U20 World Cup, the nation’s first since 1966.
Talk about pressure and expectation.
He held his nerve in the World Cup final and did it again at Rugby Park.
Shoot-out hero Woodman was exceptional in saving from Eamonn Brophy, Greg Taylor and Greg Kiltie in a high drama quarter-final replay shoot-out.
This was a scrappy, nervy tie, but in cup football progressing is primary, the performance secondary.
The last time Aberdeen won a trophy, the League Cup in 2014, they edged past Alloa Athletic on penalties in the early rounds.
For those who believe in omens – Aberdeen have won the trophy the three previous times they have faced Killie in the Scottish Cup – 1970, 82 and 84.
This battling win did not come without collateral damage, however, as three players picked up yellows that will rule them out of the semi through suspension.
Skipper Graeme Shinnie, Kenny McLean and Shay Logan will miss the clash with Motherwell.
In the build-up to the replay, Killie boss Steve Clarke had sparked a war of words with Dons gaffer Derek McInnes over Jordan Jones’ part in the equalising penalty in the original tie.
Clarke attempted to ramp it up further by this week claiming all the pressure was on Aberdeen as it was make or break for their season.
It should come as no surprise Clarke should attempt to use mind games to tip the balance in favour of his team.
He was assistant to Jose Mourinho, the Chosen One of manipulation, at Chelsea for three years.
Ultimately, McInnes had the final word though and his team won the mind-games by holding their nerve in the penalty shoot-out.
Clarke was right, however, that this was make or break for the Reds.
Last season Aberdeen played in both cup finals and secured runners-up spot in the league for a third consecutive year.
Having exited the League Cup at the quarter-final to Motherwell to crash out at the same stage in the Scottish Cup would have been regression.
Yet there was also an uncharacteristic weight of expectation on Killie as one of the form teams in the Premiership.
They had lost just twice in 20 games, both to Aberdeen, but had defeated both Rangers and Celtic at home.
It made for the bizarre situation of some pundits viewing Killie as favourites, even though the Reds were unbeaten in 18 against them with 15 wins.
Aberdeen made two changes to the side which was held 0-0 at relegation battling Partick Thistle at the weekend.
Adam Rooney came in for Stevie May with Gary Mackay-Steven replacing Dominic Ball.
Kilmarnock created the opening opportunity in the seventh minute when Kris Boyd shot on the turn from 15 yards, but Woodman saved.
Moments later, Shinnie shot on the half volley from 22 yards, but keeper Jamie MacDonald comfortably collected.
There was tension in the air and it boiled over in the 23rd minute when Mackay-Steven went down with the ball close to his chest when he was on the deck.
Rory McKenzie went in with an over-zealous attempt to get the ball.
It sparked a stramash with players from both sides racing to the incident.
Referee Steven McLean booked McKenzie, who was fortunate to remain on the park.
McLean was booked for a foul on McKenzie soon after, but although he knew he was out of the semi, he was hugely influential in the bid to get there.
In the 35th minute, he unleashed a vicious 25-yard drive which flashed inches wide.
Logan then saw his hopes of a semi spot killed when he impeded Jones and was cautioned.
In the 61st minute Woodman produced a vital block to deny Boyd from close range. From a long throw the ball fell to Stuart Findlay 15 yards out, but his snatched shot flashed inches wide in the last chance of regulation time.
Disaster struck for Aberdeen in the 95th minute when a long clearance upfield bounced in front of Logan.
The full-back jumped to head it and appeared to be impeded by Brophy.
With Logan pole-axed Brophy capitalised to square the ball to Stephen O’DONNELL, who slammed home from 15 yards beyond Woodman.
The resilient Dons hit back in the 103rd minute from the penalty spot. May was manhandled to the ground by Kirk Broadfoot as he attempted to turn on goal.
MCLEAN stepped up and calmly converted the penalty low to the right of the keeper.
Moments later, he unleashed a rasping 25-yard drive that smashed off the cross-bar.
With one minute remaining, Nwakali unleashed a superb 35-yard effort, but MacDonald produced a diving save of equal quality.
Step up Woodman for the penalty shoot out.
At 1-1 he brilliantly tipped a Brophy spot kick on to his right hand post.
Then the on-loan keeper blocked a poor penalty from Greg Taylor.
McGinn rattled his spot kick off the cross bar to give Killie hope.
But Woodman extinguished that by saving from Kiltie to spark delight in the 1,494 strong travelling Red Army.
ABERDEEN: Woodman, Logan, O’Connor, McKenna, Considine, Shinnie, McLean, Christie, McGinn, Mackay-Steven, Rooney.
Subs: May (for Mackay-Steven 65), Stewart (for Rooney 77), Nwakali (for Christie 88).
Subs not used: Rodgers, Reynolds, Arnason, Ball.
KILMARNOCK: MacDonald, O’Donnell, Broadfoot, Findlay, Taylor, Power, Dicker, Mulumbu, McKenzie, Jones, K. Boyd.
Subs: Brophy (for McKenzie 70), Erwin (for K Boyd 90), Tshibola (for Power 105), Kiltie (for Mulumbu 118).
Subs not used: Fasan, S Boyd, Simpson.
Referee: Steven McLean.