There were three changes for the Dons off the back of their win in Stavanger on Thursday night. Ash Taylor, Funso Ojo and Niall McGinn all came back in to the starting XI, with Dylan McGeouch and Tommie Hoban dropping to the bench and Scott McKenna absent from the squad. Bruce Anderson, Ronald Hernández, Dean Campbell and fit again Ryan Edmondson were also added to subs' bench.
Motherwell made two changes from the team that drew 2-2 after extra-time at Coleraine on Thursday, before winning through 3-0 on penalties. Nathan McGinley and Callum Lang dropped to the bench, Liam Grimshaw and Chris Long replacing them.
On a bright and breezy day, the visitors were in front after just four minutes, referee Beaton the only man to spot a handball in the Dons' area from Marley Watkins from a Motherwell free-kick, the visitors all running back to form up after the whistle thinking it was given for offside. Given the opportunity, O'Hara sent Joe Lewis the wrong way from the spot, burying the ball in the opposite corner.
Things went from bad to worse five minutes later, a poor clearance from Lewis going straight to Long 25 yards out and he strode forward before slotting the ball across the goalkeeper and into the far corner.
The Dons looked lethargic but there was better from them at last in the 14th minute, Jonny Hayes spearing a wicked cross through the six yard box, just inches in front of the onrushing forwards, a narrow escape for the visitors. Within a minute, Hayes was on the floor and needing treatment before he eventually resumed.
Motherwell were enjoying much the better of the play against a strangely hesitant Aberdeen and midway through the half, it was 3-0. A Polworth corner flew to the back post where Mugabi got free of his marker, attacked the ball and bulleted a header past Lewis, who got a hand to the ball but couldn't keep it out. Ross McCrorie was claiming a foul, but there was nothing doing from the referee.
Nice interplay involving Ryan Hedges and Niall McGinn ended with a ball into Watkins in the box, the striker going down under challenge from Mugabi in the 40th minute but the referee gave the Motherwell man the benefit of the doubt.
Further proof that this wasn't Aberdeen's day came in the 43rd minute, Andy Considine curling in a lovely cross on the run from wide on the left, picking out Watkins who headed it down, past Carson, but the ball clipped the inside of the post and bounced back to safety. At least Aberdeen were now beginning to ask some questions of the visitors, offering some crumbs of encouragement for the second half.
HALF-TIME: ABERDEEN 0 MOTHERWELL 3
Aberdeen were out early for the second half, three changes made with Shay Logan, Tommie Hoban and Ryan Edmondson all on in place of Taylor, Ojo and McGinn.
It was a good start by the hosts, Hedges setting Wright away down the right, his low cross just missing a red shirt. As Motherwell broke from there, Logan collected a booking for a foul on halfway. McCrorie soon followed him into the book for a foul on Watt.
Frustration was building as the hour approached, Motherwell sitting in and protecting their lead, looking to hit on the break when the chance arose, Aberdeen trying to find a way back into the game. Ferguson drove a shot wide of goal from a Hedges corner in the 61st minute, but Motherwell were always dangerous on the counter, Polworth stabbing a shot just over from 25 yards out a couple of minutes later.
Connor McLennan joined the fray in place of Wright in the 66th minute as Aberdeen made a fourth change. Ferguson became the third man to get a yellow card for a tackle on Watt with 20 minutes to go, Motherwell then making their first change, Long replaced by White.
Good work from Edmondson down the right created a chance for Watkins at the near post, Watkins unable to get enough wrap on the ball to turn it in from a tight angle in the 74th minute. The fifth Aberdeen substitution of the afternoon followed three minutes later, Watkins replaced by Anderson as the game began to drift towards its conclusion. Lang was then Motherwell's second switch, replacing Watt.
Edmondson had a rare sight of goal after good work from McLennan down the left, firing one off at goal on the turn but the ball flashed over the bar in the 82nd minute. Polworth made way for Maguire with four minutes left on the clock. An afternoon where the Dons were off the pace was summed up three minutes from time with another Ferguson shot from 20 yards that flew over the bar, Carson untroubled again.
After a terrific run for the Dons, these were 90 uncharacteristic minutes where nothing went right, an afternoon best consigned to the history books. Aberdeen move onto Thursday and to the game with Lisbon.