Dundee defeated Dundee United 2-1 at Dens Park on Wednesday night to book their place in the last eight of the Betfred Cup.
Faissal El Bakhtaoui's stunning strike was cancelled out by Billy King but Paul McGowan grabbed a 64th-minute winner for the Dark Blues.
Rangers thrashed Dunfermline Athletic 6-0 at Ibrox, with Alfredo Morelos netting a double. Kenny Miller, Bruno Alves, James Tavernier and Daniel Candeias were also on target for Pedro Caixinha's men against the Pars.
Kenny McLean scored the only goal as Aberdeen edged out Hamilton Accies 1-0 at the SuperSeal Stadium to book their quarter-final place.
Motherwell beat Ross County 3-2 after extra time in Dingwall. Gael Bigirimana opened the scoring but Alex Schalk levelled and it was 1-1 at 90 minutes. Chris Cadden restored Well's advantage but Craig Curran equalised from the spot after Charles Dunne had been sent off, only for 10-man Motherwell to win it with a Ross MacLean goal after 112 minutes.