Hearts recorded the first league win of Paulo Sergio's managerial reign as Aberdeen's disappointing start to the season continued.
Kari Arnason headed against the Hearts crossbar before Arvydas Novikovas fired the home side ahead.
John Sutton converted a David Templeton cross for Hearts' second.
Sutton slipped home his second goal after the break and Fraser Fyvie missed an excellent chance for Aberdeen, who have yet to score this season.
The Dons remain joint bottom of the Scottish Premier League with a single point while Hearts end a run of two straight defeats with their first league victory of the campaign.
The visitors started brightly and almost took the lead when Rob Milsom's corner found the head of Arnason and the Iceland international's effort smacked the bar before being cleared.
Arnason also had a shot wide during a promising spell for the Dons.
But it was Hearts who took the lead against the run of play as Novikovas picked up the ball on the right-hand side of the box, cut inside and lashed a left-foot shot into the net.
Hearts continued to press and Danny Grainger's free-kick was well held by Aberdeen goalkeeper David Gonzalez.
Scott Vernon and Darren Mackie headed off target for Aberdeen before Hearts doubled their lead.
Templeton was the architect, dancing his way towards the byline and clipping the ball across for Sutton to tap home his first goal for the Tynecastle side.
Winger Templeton then curled a shot over in the closing stages of the first half.
The Aberdeen defence was opened up again seven minutes after the interval when Scott Robinson forced the ball through to Sutton.
The striker deftly nudged the ball past Gonzalez with the outside of his right foot to extend Hearts' lead.
Fyvie dragged a shot wide from a promising position after retrieving the ball at the back post.
Rudi Skacel, who had replaced Novikovas at half-time, volleyed into the arms of Gonzalez with a quarter of an hour remaining.
And Hearts remained comfortable in the closing stages as they warmed up for Thursday's Europa League meeting with Tottenham.