A mistake from Jamie Langfield helped Dundee United on their way to a second home win over Aberdeen this season.
On 50 minutes, the goalkeeper was slow to clear and his kick hit the onrushing Noel Hunt and spun into the net.
The below-par visitors won a penalty soon after but Barry Nicholson smashed his effort over the crossbar.
Barry Robson sealed the victory, firing home after good work from Craig Conway before drilling a cute free-kick under the defensive wall to make it 3-0.
The victory lifts United up into third place, level on points with Motherwell, who lost to St Mirren.
A dreadful first half was notable only for a glaring miss from Dundee United defender Garry Kenneth.
Five minutes before the interval, the centre-half rose highest to meet a Willo Flood corner but missed the target from just a few yards out.
The previous play had been extremely scrappy, with neither side able to string together any passing sequences and lone strikers Hunt and Steve Lovell cutting isolated figures.
United had created the better openings, with Danny Grainger's shot from distance deflected wide by Zander Diamond, while Mark Kerr saw Andrew Considine block his lunging effort following Robson's cross.
The home team were again the brighter side after the interval but they had to rely on a terrible blunder from Langfield to open the scoring.
The Dons keeper was embarrassed when he dithered in possession and his attempted clearance was charged down by Hunt and cannoned into the net for the Irishman's seventh goal in seven games.
United winger Conway fluffed a good headed chance and Aberdeen immediately raced up the park to win a penalty when Lovell was flattened by the clumsy Kenneth.
But, much to the dismay of the visiting fans, Nicholson blazed the spot-kick high over the crossbar.
United began to retreat and sit deep on their lead but the Dons lacked the imagination to break them down.
With 15 minutes remaining, Conway led a United counter-attack and his cut-back was fired in first-time by Robson from 12 yards.
The skipper was then upended by Nicholson and picked himself up to place a great free-kick under the jumping defensive wall and beyond Langfield.
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
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