Aberdeen won their Scottish Cup replay against St Mirren to set up a semi-final meeting with Celtic.
Chris Maguire was credited with the Dons' fourth-minute opener, the goal resulting from a six-yard box scramble.
Scott Vernon converted Sone Aluko's cross to double Aberdeen's advantage right on half-time.
Nikola Vujadinovic's own goal three minutes from the end gave St Mirren hope but the home side managed to see out their victory.
Celtic won their rearranged quarter-final tie at Inverness, meaning a repeat of the Co-operative Insurance Cup semi-final, which saw Aberdeen lose 4-1 to the Glasgow side.