Andrew Considine's winner gives Aberdeen revenge for their League Cup defeat by Motherwell as they move up to second in the Premiership.
Motherwell manager Stephen Robinson believes his side have a "great chance" of beating Rangers in the League Cup semi-final.
Holders Celtic will face Hibernian in the Betfred League Cup semi-final, while Rangers will take on Motherwell.
Dominant Motherwell see off Aberdeen to reach their first League Cup semi-final since January 2011.
Scores, Results & Fixtures
Thursday 21st September 2017
Scottish League Cup - Quarter-final
Saturday 16th September 2017
Saturday 9th September 2017
Saturday 26th August 2017
Sunday 24th September 2017
Saturday 30th September 2017
Saturday 14th October 2017
Sunday 22nd October 2017
Scottish League Cup - Semi-final
Wednesday 25th October 2017
Audio & Video
Kris Boyd, Michael Stewart and Tom English debate who the best striker is right now in the Scottish Premiership.