Niall McGinn found himself in a similar position after a fine Hedges switch 10 minutes later, but his shot failed to trouble the goalkeeper.

Cosgrove got his second of the night with 20 minutes on the clock.

Another good move saw the striker dive to meet Lewis Ferguson's superb first-time cross and head the ball past the helpless Hamzic.

Left-back Greg Leigh, on loan from NAC Breda, also came close with a near-post flick from a Hedges cross.

Gallagher should have had the ball in the net four minutes after the interval, but after great interplay between Hedges and McGinn, the Irishman somehow fired straight at the goalkeeper from close range.

Aberdeen did go further in front just before the hour as Ferguson picked out debutant Leigh and the defender sent a header into the roof of the net from eight yards.

Scott Wright came off the bench to replace McGinn and within two minutes he stroked home a fourth from an inch-perfect through-ball from Gallagher as the Dons threatened to run riot.

And Cosgrove raised the roof at Pittodrie when he fired home his third with 10 minutes remaining.

The striker turned his man well before striking with the outside of his right boot to find the net from 20 yards.