Last updated on .From the section Scottish Premiership

Sam Cosgrove scored his sixth goal in four games for Aberdeen as struggling Hearts suffered yet another Scottish Premiership defeat at Pittodrie.

Cosgrove's double made it four goals in a week for the striker and moved Aberdeen up to second in the division, having been seventh just 11 days ago.

Hearts finished the game with 10 men after Demetri Mitchell received a second yellow card late on.

They have now lost six of their last nine Premiership matches.

For Aberdeen, they keep up the pressure on leaders Celtic ahead of the Boxing Day fixture at home against Brendan Rodgers' side.

Revitalised strikeforce

To say that Cosgrove has had a difficult time winning over the Aberdeen fans would be an understatement. Sent off minutes into his debut, it took him 17 games just to score his first goal for the club.

However, he and Stevie May - another who has struggled to impress until recently - are both enjoying a purple patch, with five goals between them in Aberdeen's previous three games.

McInnes elected to stick with a winning combination for the third game in a row, and within two minutes the pair had combined for the opener.

A poor header from Olly Lee was pounced on by May, and Cosgrove rose highest to nod the floated cross beyond the reach of debutant goalkeeper Colin Doyle.

And Cosgrove added a second in the second half from the penalty spot after Scott McKenna was bundled over by Christophe Berra.

Aberdeen were buoyant, dominating the first half with Niall McGinn and Max Lowe both threatening, while Shay Logan's cross dipped into the net only for referee John Beaton to penalise Lewis Ferguson for fouling the goalkeeper.

Hearts - who have now failed to score in their last five visits to Pittodrie - took their time to get going, but two free-kicks almost pulled them level before half-time.

A well-worked move bamboozled the Aberdeen backline and Steven MacLean should have equalised, but fired straight at Joe Lewis. Another effort fizzed past the post shortly after.

And as the game wore on, Hearts started to knock the ball about with a confidence that belied their recent struggles, but they could not make their good work count in the final third.

Hearts' frustration was apparent. At 1-0 they felt they should have had two penalties when Haring and Steven Naismith both hit the deck in separate incidents, then Mitchell was red carded after a lunge on teenager Dean Campbell.

With nine wins in their last 12 games, Aberdeen are in form and ahead of a potential Christmas cracker against champions Celtic.

Sam Cosgrove's second goal was his sixth in four games

'Aberdeen can challenge' - analysis

BBC Scotland's Tyrone Smith at Pittodrie

Aberdeen's resurgence continues - that's four wins in a row - and they showed all the qualities of a team with the credentials to be title challengers.

In Cosgrove, they have a genuine goal threat. In Graeme Shinnie and McKenna they have got a real gritty, granite spine. And in Lewis, they have a top-class goalkeeper. Add to that the sprinkling of talented young players that are currently peppering the team, and they appear to have the component parts to suggest they will be there or thereabouts when the prizes are handed out in May.

As for Hearts, another bad day at the office, and now just one win in nine league games. They will need to turn things round soon, otherwise a season that looked like promising so much might end up delivering very little.

'It was a good day's work' - reaction

Aberdeen manager Derek McInnes: "It was a good day's work and a great effort from the players. It sets up nicely for the game with Celtic on Boxing Day.

"We have had three very tight matches against them in the last three games so hopefully we can find a way and lot of things can go our way to try to make sure we have a winning outcome this time."

Hearts manager Craig Levein: "It's frustrating. I was much happier with the team's performance than I was the previous week. I do honestly think there was nothing in the game.

"I think we should have had two penalties. [Peter] Haring has a free header at goal, and Steven Naismith is hauled to the ground 10 yards from the referee. I spoke to the referee and he says he hasn't seen it."