Dundee United 0-2 Aberdeen

• Dons and United now level on 31 points

• Adam Rooney up to 17 goals this season

• Goalkeeping error by Radoslaw Cierzniak

• Aberdeen won five of last six in league

On-song Aberdeen registered their third consecutive Tannadice win, beating Dundee United comfortably to go level with them in the Premiership.

Adam Rooney took his season's tally to 17, pouncing on goalkeeper Radoslaw Cierzniak's error for the first before adding a straightforward second.

United's best chance of an exciting first-half fell to Chris Erskine, who was foiled by Dons 'keeper Scott Brown.

But the hosts failed to threaten in a less entertaining second half.

That will frustrate Tangerines manager Jackie McNamara, given the 3-0 beating they administered to Aberdeen on the opening day of the campaign.

And so, too, will the fact this was United's first home defeat since losing to Aberdeen in May.

The August loss clearly still rankled the Dons, who were eager to right that wrong and make it five wins from their last six in the Premiership.

Aberdeen have won five of their last six games in the Scottish Premiership

Derek McInnes's men started brightly and almost took the lead when Niall McGinn's 20-yard shot struck the top of the bar via a deflection off United's John Rankin.

Tell-tale signs of United settling were apparent, with Erskine and Stuart Armstrong combining well, but accurate final balls did not follow.

Instead, a Cierzniak mistake did. The Polish goalkeeper inexplicably failed to gather a weak David Goodwillie header from McGinn's free-kick, letting it come back off his chest and into the path of Irishman Rooney, who converted easily.

Paul Paton fizzed a 25-yard strike narrowly over as United tried to respond immediately, then Armstrong helped Erskine beat the offside trap, only for the former Partick Thistle midfielder to see his low shot saved by the legs of Brown.

Cierzniak was called upon to deny Peter Pawlett from a tight angle but the goalkeeper would be beaten again shortly after.

A lovely chipped cross by Jonny Hayes found Andrew Considine at the back post and his centre left Rooney with another simple finish to double Aberdeen's advantage.

Almost immediately, another Considine delivery from the left fell to McGinn and only the inside of the near post prevented the forward making it three by half-time.

On the hour-mark, the former Dundee United forward Goodwillie had his best chance to score against his old employers, shooting over from 10 yards.

And, with a lack of any real United threat, Aberdeen's Pawlett was played through, but his low effort was turned over the bar by the onrushing Cierzniak.

The Celtic management team of Ronny Deila and John Collins were at Tannadice