Rangers will face Celtic in the semi-final of the Scottish League Cup, while Championship side Greenock Morton will face Aberdeen.
It will be the second Old Firm clash of the season after Celtic thumped their Glasgow rivals 5-1 in their first Premiership meeting on 10 September.
Rangers beat Queen of the South 5-0 on Tuesday, while Celtic beat Alloa 2-0.
Morton, in their first League Cup semi-final for 37 years, will face Aberdeen, who pipped St Johnstone 1-0.
Morton beat fellow Championship side Dundee United 2-1 in the quarter-finals.
The semi-finals will be played on the weekend of 22 and 23 October.
Aberdeen manager Derek McInnes started his playing career at Morton, making over 200 appearances for the Greenock side.
"I am pleased Morton are in the semi-final, that is my club," McInnes told BBC Scotland. "They gave me my start.
"I have huge respect for everyone there, and the work that the chairman and [manager] Jim (Duffy) are doing. I'm delighted they're doing so well.
"It'll be interesting playing against them. Hopefully we will go there in form, hopefully we can keep this killer instinct and winning mentality we have discovered going."