Aberdeen were masters of their own downfall against Dundee United as they conceded a calamitous opening goal and then missed a penalty before Barry Robson struck twice late on to clinch a 3-0 victory for the Tannadice club.

United's opening goal bordered on comical as Jamie Langfield drove his clearance off Noel Hunt and could only look on in despair as the ball rebounded into the net.

Barry Nicholson then missed a penalty after Steve Lovell had been fouled by Garry Kenneth and Robson compounded a miserable afternoon for Aberdeen when he fired a powerful shot past Langfield from Craig Conway's cross, prior to finding the net with a well-struck free-kick.

It was United who created the better openings early on, with Danny Grainger's shot from distance deflected wide by Zander Diamond, while Mark Kerr saw Andrew Considine block his effort after lunging forward to meet Robson's cross.

Langfield was then finally called into action but it was only to make an easy save from Hunt's tame volley.

Aberdeen certainly took their time in building their first serious attack of the game and when it arrived Nicholson was presented with a wonderful opportunity to break the deadlock.

Nicholson won the ball in midfield and exchanged passes with Steve Lovell before charging through on goal.

However, after moving into the penalty area the former Rangers player opted to cut back on his right-foot and this allowed Sean Dillon to block his resultant shot.

Lovell headed the rebound back across goal but Dillon was once again well placed to clear.

With five minutes remaining before the interval it was United's turn to miss a clear-cut chance.

Willo Flood delivered an excellent inswinging corner from the left wing which picked-out Kenneth at the back post.

The United defender rose high above Considine to make contact with the ball but could only direct his header wide from barely a couple of yards out.

Kenneth went someway towards making up for that miss shortly afterwards as he made a crucial interception to stop a cross from Richie Byrne which fizzed in from the left as the first half ended in an evenly-contested stalemate.

It took only five minutes following the restart for United to move into the lead and their goal could not have arrived in more bizarre circumstances.

Langfield had plenty of time to steady himself before directing a clearance up the park but only succeeded in driving his kick against Hunt and could do nothing to stop the ball from bouncing into his unguarded net.

The afternoon then went from bad to worse for Aberdeen, as they blew a brilliant opportunity to restore parity just six minutes later.

As Lovell and Kenneth raced alongside each other to reach the ball inside the host's penalty area, the Aberdeen striker was bundled to the turf by his marker.

Referee Craig Thomson awarded a spot-kick but from 12 yards out Nicholson smashed his shot over the crossbar.

United were determined to take advantage of the good fortune that came with Nicholson's penalty miss and in the 71st minute Flood embarked on a surging run only for his composure to desert him at the crucial stage as he shot well over.

Nevertheless, the home side then doubled their advantage when good play from Conway saw the winger pick out Robson, who smashed a searing shot past Langfield from 16 yards out.

Aberdeen pushed forward following the concession of that goal, determined to try to salvage something from the game.

But the gaps they left at the back were then exposed as Robson's drive forward was only halted by a crude challenge from Nicholson.

Robson was not to be denied his second goal of the game though and proceeded to drive the resultant free-kick past a stranded Langfield to cap a terrific afternoon for United.

Teams:

Dundee Utd McLean, Dillon, Kenneth, Wilkie (Swanson 46),Grainger, Flood, Kerr, Gomis, Conway (Odhiambo 86), Robson,Hunt, Swanson (Buaben 90).

Subs Not Used: Zaluska, David Robertson, Milligan,

Johnny Russell.

Booked: Kenneth.

Goals: Hunt 50, Robson 77, 84.

Aberdeen Langfield, Mair (McNamara 46), Diamond,Considine (Maguire 71), Byrne, Young, Nicholson, Severin,Aluko (Mackie 62), Jamie Smith, Lovell.

Subs Not Used: Soutar, Duff, De Visscher, Stuart Smith.

Booked: Considine, Mackie, Young.

Att: 8,579

Ref: C Thomson (Scotland).