ABERDEEN blew away Ladbrokes Championship leaders St. Mirren with a stunning display of attacking football at Pittodrie this afternoon to book their place in the fifth round of the William Hill Scottish Cup.

The Paisley club, eight points clear in the Championship, had been tipped to give their rivals, sitting in second spot in the Premiership, a tough game in the pick of the fourth round ties.

But Derek McInnes’s side looked fresh in their first game back after the winter shutdown and defeated Jack Ross’s team with ease.

An Adam Rooney penalty and a Ryan Christie double gave them a 3-1 lead at half-time and Gary Mackay-Steven netted a sensational long-range effort in the second half to end the game as a contest.

Gavin Reilly netted for the visitors in the opening 45 minutes, but at no stage did his second tier side look capable of pulling off an upset and progressing in a match watched by 9,848 supporters.

St. Mirren got off to the worst possible start when they gifted their hosts a penalty in the eighth minute. Stelios Demetriou brought down Greg Stewart with a clumsy and needless challenge and referee Don Robertson rightly pointed to the spot. Rooney stepped up and drilled the spot kick low beyond Craig Samson.

When Christie rounded off a well-worked attacking move 10 minutes later – Graeme Shinnie supplied Mackay-Steven in the opposition area, the winger cut the ball back from the byline and his team mate side-footed a shot into the net – it looked as if the tie was over.

But St. Mirren responded well. The visitors pulled a goal back in the 25th minute when Joe Lewis could only palm a powerful volley from Lewis Morgan into the path of Reilly. The striker hooked the ball beyond the exposed keeper.

The Championship club’s revival was short-lived. Aberdeen pulled two ahead again eight minutes after that. The ball broke to Shay Logan inside the St. Mirren area and the left back did superbly to chip it over the heads of the visiting defence. Christie ghosted in and headed beyond Samson from a tight angle.

Mackay-Steven secured his side’s safe passage to the fifth round of the competition with the best goal of the afternoon shortly after the second half got underway. He unleashed a ferocious left foot shot from the corner of the penalty box which soared beyond the helpless Samson and into the top right corner of the net.

There is an awful lot of football still to be played in this competition, but the winger’s effort will be a strong contender for goal of the tournament after the final in May.

Ross put on Ryan Flynn for Ian McShane, Danny Mullen for Gavin Reilly and Mark Hill for Gary Smith after that. His team couldn't be faulted for a lack of effort at any stage in proceedings, but they were outclassed by McInnes's men and were comfortably beaten.

Niall McGinn, who returned to Aberdeen this month after a spell in South Korea, came on for Mackay-Steven to a hero’s welcome from the home support in the 66th minute. He nearly netted with a scissor kick shortly after taking to the field.

Aberdeen were beaten at the death by Celtic in last year's Scottish Cup final at Hampden and on this evidence they are determined to atone for that disappointment.