Match ends, Motherwell 0, Aberdeen 2.
Ten-man Aberdeen secured a League Cup quarter-final victory with a spirited performance against Motherwell.
John Sutton had a goal disallowed for the hosts before the Dons had Joe Shaughnessy sent off.
Motherwell's Shaun Hutchinson struck the crossbar from a corner before Andrew Considine headed the Dons ahead.
And Jonny Hayes cemented Aberdeen's semi-final place alongside Hearts, Inverness and St Johnstone by firing home on the break in injury-time.
The feat was all the more remarkable given Derek McInnes's side played more than 78 minutes a man down.
In truth, the Dons looked slightly fragile right from kick-off and were relieved to see an early Sutton strike chalked off for offside.
The hosts raged when referee John Beaton disallowed it a good 10 seconds after Sutton curled the ball into the top corner, but it had only come to the big Englishman because an Aberdeen clearance had rebounded off Motherwell's Stuart Carswell.
Soon afterwards, Beaton showed Aberdeen right-back Shaughnessy a straight red card for a lunge on Zaine Francis-Angol near the halfway line.
Calvin Zola was sacrificed as McInnes brought on Considine to shore up the defence.
Every touch of Francis-Angol from that point on was booed by the Dons fans, who clearly thought he had made too much of the challenge - and their anger increased when Hutchinson took out Peter Pawlett only to receive a booking.
It seemed a Motherwell opening goal was imminent but neat football, which allowed half-chances for Estonian Henri Anier and Simon Ramsden, failed to produce a breakthrough.
At the other end, Motherwell goalkeeper Gunnar Nielsen dropped a cross which almost fell nicely for Niall McGinn.
McGinn then robbed Hutchinson and bore down on goal before a desperate block by Stephen McManus thwarted the Northern Irishman.
A serious-looking injury to Dons left-back Clark Robertson meant McInnes had to introduce his second substitute before half-time - Scott Vernon entering the fray.
Motherwell appealed unsuccessfully for a penalty after the break when Mark Reynolds felled Anier on the edge of the box.
Aberdeen goalkeeper Jamie Langfield saved from Stuart Carswell as the hosts searched for the opening goal - and the visitors breathed a sigh of relief when Hutchinson's header came back off the bar.
The breakthrough finally came when Considine popped up at the back post to convert Hayes's corner after Pawlett's shot had been beaten wide by Nielsen.
Under the cosh in injury time, one became two as Aberdeen countered and Hayes smashed in high at the near post after being fed nicely by Vernon.
- 5HutchinsonBooked at 28mins
- 18CarswellBooked at 50mins
- 8LawsonSubstituted forAinsworthat 45'minutes
- 24AnierSubstituted forMcHughat 68'minutes
- 2ShaughnessyBooked at 14mins
- 3RobertsonSubstituted forVernonat 45+2'minutes
- 4AndersonBooked at 81mins
- 7Zola-MakongoSubstituted forConsidineat 21'minutes
- 16PawlettSubstituted forRobsonat 85'minutes
- John Beaton
- Shots on Target
Second Half ends, Motherwell 0, Aberdeen 2.
Goal! Motherwell 0, Aberdeen 2. Jonathan Hayes (Aberdeen) left footed shot from the left side of the box to the top left corner. Assisted by Scott Vernon.
Corner, Motherwell. Conceded by Barry Robson.
Attempt missed. Niall McGinn (Aberdeen) right footed shot from outside the box is just a bit too high.
Attempt missed. Scott Vernon (Aberdeen) right footed shot from outside the box is too high.
Foul by Shaun Hutchinson (Motherwell).
Jonathan Hayes (Aberdeen) wins a free kick in the defensive half.
Attempt missed. Robert McHugh (Motherwell) right footed shot from the centre of the box is too high.
Substitution, Aberdeen. Barry Robson replaces Peter Pawlett.
Goal! Motherwell 0, Aberdeen 1. Andrew Considine (Aberdeen) header from very close range to the high centre of the goal. Assisted by Jonathan Hayes with a cross.
Corner, Aberdeen. Conceded by Steven Hammell.
Attempt saved. Peter Pawlett (Aberdeen) right footed shot from outside the box is saved in the bottom left corner.
Russell Anderson (Aberdeen) is shown the yellow card.
Keith Lasley (Motherwell) wins a free kick in the defensive half.
Foul by Russell Anderson (Aberdeen).
Corner, Aberdeen. Conceded by Simon Ramsden.
Stephen McManus (Motherwell) wins a free kick in the attacking half.
Foul by Scott Vernon (Aberdeen).
Attempt missed. Simon Ramsden (Motherwell) right footed shot from outside the box is high and wide to the right.