Three first half goals sent the Dons on their way to a Hampden semi-final in January as they saw off a spirited challenge from Partick Thistle at Pittodrie.
There were three changes to the Aberdeen side that beat Hearts 2-0 at Pittodrie on Sunday. Jack MacKenzie, Connor Barron and Jayden Richardson all started from the bench with Hayden Coulson, Matty Kennedy and Vicente Besuijen returning to the starting XI. Kennedy made his 50th start for the Dons.
Partick Thistle made two changes to the side that won 2-1 at Hamilton Accies on Saturday. Brian Graham and Aiden Fitpatrick were on the bench, replaced by Anton Dowds and Scott Tiffoney.
The Dons should have been ahead on three minutes. Kennedy played into Duk who sent Besuijen away down the right and his chipped ball from the by-line to the back post found Leighton Clarkson with the goal at his mercy. His header wasn't strong enough and a Thistle defender was able to clear. Thistle responded two minutes later, Kelle Roos diving to his left to paw away a 25 yarder.
Muirhead took the game's first booking on 10 minutes, hoiking Duk to the ground 25 yards out as he ran towards goal. Sadly, the free-kick from Clarkson came to nothing.
There was no stopping Duk on 16 minutes though. Coulson won the ball on halfway, threaded it through to Duk. After accelerating into the box, he crashed a low left footer under Sneddon and in. 1-0.
Muirhead was not far away from the early bath a minute later, Duk on the rampage again down the left, Muirhead scything him down but, he escaped a second booking. Patrick quite sensibly made a change in the 23rd minute, Muirhead replaced by Hodson, perhaps to ensure they kept 11 men on the pitch.
Coulson was on the chase on 24 minutes, but his cross was behind the Aberdeen strikers as they flooded into the box. Ross McCrorie was next to come forward a minute later, blasting a 25 yarder over the bar.
Clarkson wasn't far away in the 29th minute, controlling a fierce ball into him from Ylber Ramadani, his 20 yarder swerving just away from goal at the last moment.
It was 2-0 on the half hour, a Holt own goal. Clarkson initially did well to win the ball on the right of the six yard box. His cross reached Bojan Miovski who helped it into the path of Coulson. His shot across goal took one deflection then cannoned off Holt, left Sneddon wrongfooted and nestled in the bottom corner.
Two minutes later, Milne made a good run forward to collect the ball of Tiffoney, firing in a low shot from the edge of the box, but it was a straightforward save for Roos down to his right.
Coulson did it again on 34 minutes, driving forward down the left and firing off a 20 yarder that smacked off McMillan and flashed past Sneddon for 3-0 as the Dons looked to try to settle the tie before half-time.
It was nearly 4-0 on 43 minutes, Miovski setting Clarkson away down the right. His return pass across the box found Miovski a dozen yards out, but his stabbed shot was cleared off the line to safety. Holt went down injured as Aberdeen had poured forward and the stretcher was called for to help him off the field with what appeared to be an injury to his left knee. Akinola replaced him.
There was time for Liam Scales to play a beautiful 40 yard pass into Besuijen but his first touch was a shade too heavy, giving Sneddon the chance to get off his line to smother the ball.
HALF-TIME: ABERDEEN 3 PARTICK THISTLE 0
Aberdeen made one change as Christian Ramirez and Connor Barron replaced Miovski and Clarkson at the break. Brownlie replaced Tiffoney for Partick.
Ramirez was straight into the thick of it too, playing a one-two with Duk around the top of the box before bending the ball just over the bar in the 47th minute. He then played Duk into space in the penalty area a minute later, Duk's effort deflected wide.
Thistle pulled one back in the 52nd minute. A corner was flighted to the back post and Brownlie got up highest to head downwards, the ball creeping past Roos and just inside the post.
The Dons almost replied immediately. Coulson brought the ball forward before passing out to Ramirez on his left. From a tight angle, the American striker tried to squeeze the ball in but Sneddon did well to save with his legs.
There were two more Thistle changes on 58 minutes, Dowds and Docherty making way for Graham and former Don Cammy Smith.
Ramirez had another pop on 59 minutes, the ball sitting up nicely for him 30 yards out, his first time crack at goal clawed away from the top corner by Sneddon. Duk was then replaced by Shayden Morris after 62 minutes.
The visitors certainly weren't lying down, Hodson trying his luck from distance, the ball flying wide in the 66th minutes as the Championship side looked to exert some pressure on the Dons who were lacking some of that first half intensity. McCrorie was in the book on 73 minutes, forced to drag Smith to the ground after a poor ball out from Roos. Ryan Duncan joined the fray in place of Besuijen on 78 minutes as Aberdeen looked to find some rhythm to their play again.
A lovely passing move sliced Thistle open on 84 minutes, culminating in Sneddon producing a fine save to tip the ball over the bar from Kennedy's 20 yarder. The corner was initially cleared but Aberdeen recycled the ball, Duncan stepping inside on the left edge of the box to slam a right footed cross across the face of goal and into the far corner, a terrific finish to seal the tie.
Thistle kept going though, Graham drifting inside on 87 minutes to fire off a low shot from 20 yards, another straightforward take for Roos. Credit to the Championship side, they'd made life difficult for the Dons in the second half, but that first half salvo had been just too much for them to handle.