Half-time substitute Niall McGinn was the star of the show as Aberdeen comfortably overcame Queen of the South 4-1 to move into the quarter-finals of the William Hill Scottish Cup.

McGinn netted the opener, and though Stephen Dobbie's stunning strike briefly brought parity, the Dons winger turned provider for Andrew Considine and Sam Cosgrove to head the Dons into a 3-1 lead.

Cosgrove would then add a fourth from the penalty spot.

The Dons had started brightly, with Shay Logan heading wide from a Stewart cross after eight minutes, but that was not to prove an indication of things to come, as the game developed into a scrappy midfield battle.

While the home side had a territorial advantage, the best effort of the opening half fell to the Doonhamers, with Michael Doyle's break on the counter seeing him play in left-back Jordan Marshall who took a touch before unleashing a 30-yard rocket that had Joe Lewis at full stretch to push over.

Indeed, it was injury time before Queens' keeper Alan Martin was tested again, his claim from Max Lowe's right-footed shot all too easy.

If the first half had failed to kick into life, the second started in top gear.

McGinn replaced Stevie May at the break, and within two minutes he had opened the scoring, firing high into the net as the ball broke kindly after Kyle Jacobs tackle on Cosgrove.

The lead lasted only three minutes, and the equaliser came out of nowhere.

While it would be churlish to suggest there was little danger when Dobbie picked up the ball 40 yards out, it was still a little surprising to see him unleash a 30-yard snap-shot into the top-left corner for his 38th goal of the season.

The floodgates were open now, and McGinn turned provider when his cross from the right, after a Gary Mackay-Steven short corner, was powered into the net from six yards by Considine.

McGinn was enjoying himself and he was involved again as Cosgrove made it 3-1, this time crossing from the right for the prolific Dons hitman to head home his 15th of the campaign from similar range.

Cosgrove found the net again after 73 minutes, this time from the penalty spot after Andrew Stirling was harshly adjudged to have handled a Logan shot, the ball having come off the midfielder's chest.

Undeterred by the lengthy protests, Cosgrove calmly struck into the bottom-right corner.