Steven Naismith's return from knee surgery couldn't halt Hearts' frustrating run of form as they suffered a seventh defeat in ten games.
Sam Cosgrove's two goals decided this festive affair to give Aberdeen their fourth successive victory – and Hearts finished the match with ten men following Demetri Mitchell's late red card.
Cosgrove headed the first in the opening minute and then dispatched a second-half penalty, taking his scoring total to six in his last four appearances. He was a handful for the Hearts defence throughout this match.
Irish international goalkeeper Colin Doyle was granted his Hearts debut as Zdenek Zlamal paid the price for a recent form dip. Doyle was left picking the ball out of his net before he had even touched it due to Aberdeen's incisive start – which set the foundations for this result.
Naismith made a welcome return after knee surgery to reinforce the visitors' attack. After defeating Dundee 5-1 in their previous fixture, it was no surprise to see the Aberdeen manager Derek McInnes name an unchanged team.
Those in red continued in the same vein by scoring inside the opening minute. Stevie May's cross from the byline prompted Cosgrove to rise for a looping header high into Doyle's top left corner. The imposing Englishman was a constant thorn in Hearts' side due to his height and physicality.
A second Aberdeen goal was disallowed for a foul by Lewis Ferguson on Doyle as Shay Logan's high cross dropped on the keeper. The hosts had enjoyed a dominant start but an intricate passing move from a free-kick fashioned Hearts' best opportunity of the first half on the half-hour. Olly Lee and Sean Clare linked up before Oliver Bozanic slid a through ball to MacLean, whose shot was blocked by the emerging Joe Lewis in a one-versus-one.
Referee John Beaton missed a clear foul by Aberdeen's Max Lowe on Naismith as the ball was played through to MacLean, denying the visitors a certain penalty. MacLean's headed flick from another Lee free-kick bounced wide of target, offering further evidence that Hearts had forced their way back into this encounter by half-time. They appealed for another penalty moments into the second period when Peter Haring fell in a challenge with Niall McGinn, but Beaton didn't agree.
Niggling exchanges took place in various areas of the pitch between two very competitive teams. That had an adverse effect on the quality of football at times. The result was put beyond doubt on 69 minutes when Cosgrove struck his second of the afternoon from the penalty spot.
Scott McKenna fell inside the Hearts area as McGinn's free-kick arrived and Beaton immediately signalled a foul. After some protests by visiting players, Cosgrove confidently sent Doyle the wrong way from 12 yards to give his team the two-goal cushion they wanted.
Naismith was cautioned along with the Aberdeen substitute Stephen Gleeson after tempers flared in midfield. The Scotland striker appeared to catch Ferguson on the ground but it was unclear at first glance how much intent there was.
McInnes' side finished the game in the ascendancy. Mitchell's dismissal came four minutes from the end of normal time when he earned a second yellow card for fouling Dean Campbell. That summed up a miserable and frustrating afternoon for Hearts, while Aberdeen climbed to second place in the Premiership for at least 24 hours.
Aberdeen (4-4-2): Lewis; Logan, Considine, McKenna, Lowe (Campbell 49); McLennan (Wright 87), Ferguson, Shinnie, McGinn; Cosgrove, May (Gleeson 60). Unused subs: Cerny, Wilson, Forrester, Anderson.
Hearts (3-4-2-1): Doyle; Haring, M Smith, Berra; Godinho (Brandon 87), Lee, Bozanic, Mitchell; Naismith (McDonald 78), Clare (Morrison 84); MacLean. Unused subs: Zlamal, Hughes, Mulraney, C Smith.
Referee: John Beaton.