IF this was, as Derek McInnes insisted afterwards, a “rusty and sloppy” showing by Aberdeen in their first competitive outing after the winter shutdown then how good are the Pittodrie club going to be when they find form?

St Mirren, flying in the Ladbrokes Championship and virtual certainties to win promotion to the Premiership, were fancied by many to give their top-flight opponents a real game and possibly even pull off an upset in the build-up to this encounter.

They were, though, swatted aside with the minimum of fuss by adversaries who suggested they are more than capable of atoning for the disappointment they suffered in the William Hill Scottish Cup final last season, when they were beaten at the death by Celtic, in the coming months.

An Adam Rooney penalty, a first-half Ryan Christie double and a sensational Gary Mackay-Steven effort early in the second half ensured the home team’s safe progress to the next round. It was a dominant display against rivals who have been showered with plaudits for the way they have performed this term, albeit in the second tier. It augurs well for the remainder of the 2017/18 campaign.

Aberdeen went on an excellent run after a similar cup win this time last year, secured a third successive runners-up spot in the league and reached the cup final. It would be no great surprise if they emulate that hot streak again given the quality of their play at times yesterday. They excelled in every department.

Certainly, Rangers, who they face in a Premiership game at Ibrox on Wednesday night, would seem to have a real battle on their hands to beat them to second place in the league table despite the players they have brought in during the January transfer window.

“Last season we came back from the three-week break and had a straightforward game against Stranraer here,” said McInnes. “The game helped us. It set us up for the league campaign.

“We were a bit sloppy and bit rusty in our decision-making at times against St Mirrren. We gave them too much encouragement for my liking. But we had good spells in the game, scored some fantastic goals and got the job done. We will be better for having had the game.”

St Mirren got off to the worst possible start when they gifted their hosts a penalty in just 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 coolly side-footed a shot into the net – it looked distinctly like the game was finished as a contest.

However, 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 to the feet of Gavin Reilly. The striker hooked the ball beyond the exposed goalkeeper.

Their revival, though, proved 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 well to chip it over the heads of the flat-footed 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 into the top right corner of the net.

“I don’t think you will see many better goals this season,” said McInnes.

Ross sent on Ryan Flynn for Ian McShane, Danny Mullen for Gavin Reilly and Mark Hill for Gary Smith after that. While his team could not be faulted for effort at any stage in proceedings they were out-fought and out-thought by a superior side and were comfortably beaten.

“It was a good learning experience for us, individually and as a team,” said Ross, putting a positive spin on events. "It's really good for the players individually, some of the younger ones, to see the levels they need to get to because there's a difference physically as well, not necessarily the height and weight of players, just the manner they go about it.”

Ross, whose team return to league action with an away game against third-placed Dunfermline at East End Park on Friday night, has no concerns about this chastening experience impacting negatively on St Mirren’s push for promotion.

“Every time we have had a setback in the league this season, which they hasn't been many of, we've always responded with a win, so I have no question they will do that,” he said.

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

Stevie May, who has been sidelined as a result of an injury suffered when Ryan Jack fouled him in a game against Rangers last month, also made his comeback when he replaced Stewart with 12 minutes remaining to cap a satisfying afternoon for McInnes.