Dundee United couldn’t peg Aberdeen back at Pittodrie despite the hosts going down to 10 men.
The Dons lost Barry Robson with 71 minutes on the clock when he elbowed United midfielder Charlie Telfer in the face.
The Tangerines couldn’t do anything with their man advantage, though, and Adam Rooney’s 39th-minute tap-in sealed the points for the home team.
United started the game with three at the back captain for the day Jarek Fojut, Callum Morris and John Souttar with Calum Butcher playing in front of them.
However, with just 18 minutes on the clock they changed to a back four and pushed Souttar into the centre of the park.
By then, United goalie Rado Cierzniak had pulled off a fine save with his feet off a Johnny Hayes’ shot from the left.
Butcher was the first booking on 38 minutes when he tripped Hayes and it proved to be a costly concession of a freekick by the visitors.
For the resultant setpiece was played to the back post by Robson and, as Fojut tried to usher it out for a goalkick, Mark Reynolds stuck out a boot and hooked the ball goalwards.
Cierzniak saved at the tightest of angles but the loose ball spun up and Rooney tapped it over the line to make it 1-0 to the Dons with just six minutes of the first half remaining.
With just seconds of the second half gone, United striker Mario Bilate fell to the ground clutching his hamstring. He was replaced by Robbie Muirhead.
A slack pass from Fojut on 54 minutes was picked up in midfield by Willo Flood, whose 25-yard low drive had to be pushed around the post by Cierzniak.
Ryan McGowan was booked for a challenge on Hayes on 58 minutes before Chris Erskine had a go for United with a well-hit shot from outside the box that Dons goalie Scott Brown could only hold at the second attempt.
Sub Muirhead then did well to race up the left before cutting inside and stinging Brown’s hand with a strike.
On 71 minutes, the Dons were reduced to 10 men when Robson elbowed Telfer in the face just yards from standside assistant referee Andrew McWilliam. It was a clear sending-off offence and a moment of madness from the former United captain.
United brought on young Ali Coote to replace Butcher as they looked for a leveller.
They tried hard but it needed a last-ditch tackle from Souttar on Niall McGinn up at the other end to prevent Aberdeen adding to their lead in the 90th minute.