Anthony Stokes and Kris Commons each netted braces, while Efe Ambrose and Joe Ledley also weighed in with goals as Neil Lennon’s side put the visitors to the sword.
Stuart Armstrong scored in the 10th minute for the game’s opening goal, while Johnny Russell’s stoppage-time strike was all but a consolation effort.
Motherwell moved into second place in the table as they thrashed Inverness 3-0 at Fir Park and leapfrogged their opponents thanks to a Michael Higdon double and a goal from Nicky Law.
Hibernian moved up to fourth in the table as they beat St Mirren with Leigh Griffiths’s penalty in the 72nd minute separated the sides at St Mirren Park.
Kilmarnock put three goals past Hearts at Tynecastle as Paul Heffernan netted a brilliant hat-trick, while Ross County beat St Johnstone 1-0 at home with Ivan Sproule on target.