Class does tell, but sometimes it takes its time about it. Aberdeen laboured for 40 tedious minutes at Somerset Park last night before finally producing a goal to confirm their status as the aristocrats visiting the faded splendour of their country cousins.

There was an element of working-class socialism to the match. Every player seemed entitled to one, just one, touch. They stuck to this unspoken rule with commendable discipline. The ball was kicked about like an unfortunate in A Clockwork Orange.

Aberdeen slowly but finally asserted their authority. Restricted to a couple of corners from Charlie Mulgrew that Andrew Considine and Darren Mackie headed over, Aberdeen found space in the dying embers of a first half that was fiery if not full of finesse.

A quick break from midfield seemed to have stalled on the 18-yard line but the ball was played back to Mulgrew who curled a ball in from the left for Chris Maguire to scramble under Stephen Grindlay.

This incisive move was in contrast to a match where the ball was regularly a victim of a dull, regular hammering.

Aberdeen, perhaps haunted by the ghosts of past cup upsets, seemed determined to match Ayr United in effort. A midfield of poise and craft was thus initially bypassed. Jamie Smith, Mark Kerr and Gary McDonald were reduced to participants in a game that valued energy over ingenuity.

This midfield trio, however, had a louder say in the second half, perhaps prompted by two moments when Ayr could have restored parity. Both centred on the bulk of Martyn Campbell whose height and strength inside the box caused alarm from two corner kicks early in the second period.

The first was scrambled to safety after the centre half had discomfited Bertrand Bossu to such an extent that the goalkeeper fumbled badly. The second followed an astute header across goal by Campbell that Bryan Punty could only deposit in Bossu's arms.

These served as a signal for Aberdeen to take control of the match. Kerr and Smith were instrumental in denying Ayr possession and combined for the former Celtic player to strike a post. This outbreak of football was followed by a succession of chances for Aberdeen to consign the game to the files of routine victory.

Smith hesitated and his shot was blocked, Maguire fired past and a Considine header eluded Mackie who had only to touch the ball to put the game beyond United.

Ayr, for all their tireless efforts, drifted from the match. A lifeline in the form of a goal was only a touch away but Aberdeen were equal to forays that were bereft of subtlety.

Scott Walker was squeezed out at the back post as he attempted to make something of a long, hanging cross and substitute David Gormley provided pace in the final third.

But it was poise and precision that Ayr needed and they are in short supply in the lower divisions. Aberdeen attempted to put the game beyond dispute. The impressive McDonald volleyed smartly but was denied by a good Grindlay save and the midfielder's neat header could not evade the keeper.

Aberdeen could not have the final say with a second goal. But class had told in one first half moment. It was always likely to be too much for the honest men of Ayr.