Derek McInnes said his side have developed killer instinct after seeing them win 3-0 at Hamilton Accies to keep pace at the top of the Premiership.

A double from Sam Cosgrove and a goal from Lewis Ferguson saw Aberdeen stay in fourth place, three points behind leaders Celtic who have two games in hand.

It was Cosgrove's role in attack alongside Greg Stewart and Stevie May that most pleased the Aberdeen boss, who said his side was finally showing they know how to put the opposition to the sword.

McInnes said: "It's clear to anyone watching Sam that confidence is important to strikers.

"His first goal was scruffy but he reacted well, his second we see in training where he can open his legs and isolate a centre-back and move.

"He's worked hard at his game, knuckled down and tried to learn his profession.

"Considering where he's come from he's improving brilliantly and hopefully that continues. His game is in a good place.

"Greg is very thoughtful, gives us craft and graft and adds a bit of thought to our play.

"I'm delighted Greg's helping us with the challenges ahead and hopefully he can have a big influence on the team.

"When they're all on song there is decent movement there but the importance is being a threat.

"There wasn't a killer instinct earlier in the season. There's a goal at the end of the pitch for a reason. We seem to have grasped the importance of that."

The loss means Hamilton are two points above bottom-placed St Mirren but manager Martin Canning felt a key decision went against his side at the wrong time.

Aaron McGowan went down under a challenge from Gary Mackay-Steven in what Canning thought was a penalty call but Aberdeen went up the park to score their second goal.

Canning said: "It looked a penalty, he came the wrong side. I claimed for it. But it sums up.

"We then had poor decision making. We over commit, let their striker inside when he had nowhere to go.

"It's a game that started well but finished poorly. We had to keep it at 1-0 because as soon as it goes 2-0 they enjoy it and start knocking the ball about."