Hearts edged a controversial encounter at Pittodrie thanks to an early goal, as Aberdeen finished with just nine men.
It was the visitors who had the first effort on goal with Mark De Vries heading Austin McCann's cross straight into the arms of David Preece.
Two minutes later the same combination of McCann and De Vries saw the big striker swivel and fire a powerful right-foot shot that was brilliantly saved low to his left by Preece.
On 12 minutes the first goal did arrive and it came for Hearts when Paul Hartley swung a corner into the box and Kevin McKenna headed it into the ground.
The ball spun off the turf and was flicked on by Andy Kirk and spun agonisingly over the head of Steve Tosh and into the back of the net.
This stunned the home side into action and David Zdrilic had the chance to level the game just two minutes later, but like the rest of his team-mates he lacked confidence and conviction and blasted his effort well over the top.
Aberdeen were certainly putting a lot of effort into the game and straight from the re-start Scott Booth again created space for himself, this time down the left, and his cross was headed over by Tosh.
Hearts' Scott Severin was the next player to try his luck with a shot from 12 yards, which had Preece scrambling along his line to palm the ball away.
The Dons frustration was now showing and both Booth and Tosh picked up needless bookings for dissent.
Then on 69 minutes, an off the ball incident involving Alan Maybury and Zdrilic ended with Maybury going into the book and Zdrilic heading for an early bath as he received his second yellow card, followed by the inevitable red.
Worse was to come for the Dons in the 78th minutes when a late challenge on Maybury by Tosh saw the Dons reduced to nine men, much to the disgust of the home fans.
The home fans were incensed again following a tussle inside the area between De Vries and Russell Anderson, which ended with the Dons defender being bundled to the ground.
But referee Craig Thompson waved away the appeals of the home players The game ended with Aberdeen recording their sixth home defeat, but at least this time the Dons players showed enough fighting spirit to suggest that their dismal run might come to an end.