Brad Lyons scored the winner as Kilmarnock defeated Dundee United 2-1 at Rugby Park to set up a Premier Sports Cup quarter-final against St Mirren.
Josh Mulligan netted the clincher with a superb goal in Hibernian's 2-0 win over Livingston in West Lothian to send David Gray's side into a last-eight clash at Ibrox.
Quarter-final draw
Kilmarnock v St Mirren
Partick Thistle v Celtic
Rangers v Hibernian
Aberdeen v Motherwell
Ties to be played on the weekend of September 20/21