Derek McInnes' men thumped NSI Runavik of the Faroes 6-0, helped by a second-half hat-trick from substitute Ryan Hedges. Lewis Ferguson, Curtis Main and Jonny Hayes were also on target at Pittodrie.
Motherwell saw off 10-man Glentoran 5-1 at Fir Park, with all the goals coming in the second half. Callum Lang, Stephen O'Donnell, Liam Polworth, Tony Watt and Chris Long all scored for the Steelmen.
The draw for the next round takes place on Tuesday, with ties scheduled for Thursday September 17.