United goalkeeper Deniz Mehmet makes a mess of grabbing a cross but redeems himself as he rises to save Niall McGinn's shot.

Nothing is coming off for Aberdeen, even when the visitors add a helping hand.

Craig Levein
Former Dundee United manager on BBC Sportsound

That looks to have sealed United's win.

Aberdeen's defence make a series of blocks around their own penalty box and look to have cleared the danger.

However, Marc McNulty plays a neat one-two with Ian Harkes before the Scotland striker calmly slots it through the legs of goalkeeper Gary Woods.

Image source, BBC Sport

Frustrated Aberdeen midfielder Lewis Ferguson goes into the referee's book for a sliding challenge on Ryan Edwards.

He is the second to receive a yellow card after United's Calum Butcher.

Ouch! - Penalty appealpublished at 49mins

49mins

Aberdeen 0-2 Dundee United

Aberdeen have certainly started at a risk pace and force a couple of corners.

United goalkeeper Deniz Mehmet goes to punch clear and makes contact with Lewis Ferguson's head as the midfielder heads just wide.

However, the referee gives a goal kick.

Aberdeen get the second half under way. Can they do what Motherwell did yesterday and come back from two behind?

United manager Micky Mellon's ploy of making seven changes in midweek looks to have worked.

His returning players look to have benefitted from the rest and the 3-0 defeat by Kilmarnock is not playing on their minds.

Aberdeen, with only one change, meanwhile, look exhausted from their draw with Celtic.

Aberdeen are going to have to do something special if they are to reach their fifth Scottish Cup semi-final in a row and extend their unbeaten run to five games.

They have rarely looked like scoring their first goal against United in three and a half games this season.

Image source, SNS

Willie Miller
Former Aberdeen defender on BBC Sportsound

Tyrone Smith
BBC Scotland at Pittodrie Stadium

Dundee United have been completely dominant so far at Pittodrie, thoroughly deserving of their 2-0 lead.

In fact, they could and should, probably, have been even further ahead.

The character and quality Aberdeen showed against Celtic in midweek has been completely absent. The only plus point for the Dons is that they aren't even further behind.

Quite a half time team talk needed from Stephen Glass.

New Aberdeen manager Stephen Glass has the first crisis on his hands to deal with after three games in charge.

After a promising start, his side have been taken apart by a three-pronged United attack that at long last seems to be finding the right blend.

Marc McNulty's low drive and Ryan Edwards' header, both players scoring their fourth goals of the season, has United heading for the semi-finals unless Glass can work some half-time magic.

Image source, SNS

Almost a carbon copy of United's opener as Nicky Clark this time finds Marc McNulty, but on this occasion the striker's low drive is just wide of the far post.

At last, a response from Aberdeen.

Niall McGinn's free-kick is met by a group of bodies climbing into the sunshine and it emerges towards the top corner before goalkeeper Deniz Mehmet's fingertips turn it over.

Craig Levein
Former Dundee United manager on BBC Sportsound

Aberdeen are in deep trouble now as Ryan Edwards heads the visitors into a two-goal lead.

The big English defender rises like a flamingo above the static home defence to head home from a Nicky Clark free-kick lofted into the penalty box.

Image source, BBC Sport

Aberdeen are fortunate not to concede a free-kick on the edge of their own penalty box.

Lawrence Shankland gathers with his back to goal and falls to the ground with defender Tommie Hoban having a fistful of his shirt.

Tyrone Smith
BBC Scotland at Pittodrie Stadium

The back-up goalkeepers are certainly doing the business at Pittodrie. Both Deniz Mehmet and Gary Woods have made excellent, goal-saving stops this afternoon. United really with a stranglehold on this game now, swarming all over Aberdeen.