SAM Cosgrove, like the Aberdeen supporters, must have wondered, when he would break his scoring duck for the Dons after 15 barren appearances.

It was good news, then, that he managed not one but two strikes in this one-sided affair against a St Mirren side run ragged for most of the 90 minutes.

Yet it was Connor McLennan, in his first start and having celebrated his 19th birthday on Friday, who stole the spotlight with a spectacular goal on the half-hour mark, six minutes after Cosgrove’s opener.

It was as good as it gets for a youngster told only when he arrived at the stadium that he was in the team.

His promotion came courtesy of injuries to Stevie May and James Wilson while Niall McGinn was also unavailable.

“I was confident I could do something,” he said. “I can’t remember much about the goal and I didn’t even see it going in because the defender was blocking me.

“When it came to me, I thought I might as well hit it and thankfully it went in. It was extra special because it was my first start and my first goal.”

The omens were not good for the visitors who had failed to record a win against the Dons in 13 Premiership games and when Cosgrove’s well-executed glancing header from Shay Logan’s curling cross opened the scoring in 26 minutes it did nothing for the Buddies’ confidence.

When Max Lowe hit Aberdeen’s third, four minutes before an interval the Paisley side must have been praying for, the points were already banked and the Buddies' collapse complete.

“The goal changes it,” Oran Kearney, the St Mirren manager insisted. “They get a lift and I think that is something we have to learn.

“You can tell everyone they are the best player in the world but the one big thing is performances in games. In the four games I have been here the home games have been of a good standard but the away games haven’t. That is the alarming thing at this moment for me.”

Cosgrove’s second, a clever 65th-minute clip into the net from Lowe’s cross, exacerbated the Buddies’ difficulties and even an eye-catching chip from their energetic striker Simeon Jackson 11 minutes later, failed to muster anything resembling a positive critique of their performance.