A depleted Dons side slipped to a chastening defeat in the capital as Hearts cruised to three points, leaving Aberdeen marooned in the bottom half of the table.
There were two changes to Jim Goodwin's side after Saturday's 1-1 draw with Dundee United as back into the starting line up came skipper Scott Brown and Jonny Hayes. The injured Adam Montgomery missed out altogether, with Connor McLennan starting from the bench. Jack MacKenzie was also added to the bench. McCrorie, Ramsay and JET were also missed the trip to Edinburgh.
After Hearts won 2-0 at St Mirren on Saturday, there was just one change to their side, Ellis Simms coming in for Ben Woodburn.
The home side made a brisk start to the game but Aberdeen were committed in clearing their lines across the opening minutes. That said, Mackay-Steven was left in plenty of space 15 yards out in the fifth minute, but he miscued his shot horribly wide. Lewis Ferguson had Aberdeen's first shot a minute later, his effort from distance flying over the bar.
A swift break down the left from Boyce allowed him to fire in a dangerous looking cross on eight minutes, Hayes doing well to clear. Kingsley was next to cause trouble down the left, his centre picking out Simms on the edge of the six yard box but fortunately, he put his effort over the bar, a glaring miss.
Boyce was released in behind on 11 minutes and looked certain to score but David Bates came sliding in to get a vital block on the ball and put it behind. Hearts were finding space in good areas but fortunately, they'd yet to make it count.
Kingsley was away down the left on 18 minutes, slinging a dangerous ball into the six yard box, Hayes and Bates converging on it to clear in front of Simms, Lewis taking a real whack in the four man pile-up. He was able to carry on after receiving some treatment.
Aberdeen were on the break in the 23rd minute, Christian Ramirez darting forward from halfway, Kingsley coming across to smother the danger. Seeing Gordon off his line, the American striker then tried an audacious shot at goal from 50 yards a minute later, but the ball sailed over the bar.
The Dons did have the ball in the net on the half hour, Declan Gallagher heading home from a left wing free-kick only for referee McLean to blow his whistle. It was not clear if he was penalised for a supposed push on Simms or if there was an offside call - either way it looked a very tight decision.
Brown was booked for a challenge on Simms on 37 minutes. From the free-kick out wide on the left, there was a bout of head tennis in the box, the ball eventually dropping perfectly for Souttar 15 yards out. He caught the volley sweetly, the ball taking a deflection off Bates on its way through, flashing past Lewis to give Hearts the lead.
Ramirez tried a volley of his own on 43 minutes, this one a dipper from 25 yards, Gordon quickly down to his left to snaffle the ball.
HALF-TIME: HEARTS 1 ABERDEEN 0
The second half took some time to get going, play held up on 53 minutes when Matty Kennedy went down with injury. He was replaced by McLennan.
Hearts had a great opening to double the lead on the hour, Boyce threading McKay through. Lewis was quickly off his line to narrow the angle, making a fine save from point blank range. Sadly, it was just a stay of execution, for it was 2-0 from McKay's corner, Kingsley up above Ramirez and Gallagher in the middle of the goal to bullet his header into the net.
Aberdeen responded, Brown driving forward and finding Vicente Besuijen, his low shot deflected just wide of the near post. Hearts were back at Aberdeen again from there, Boyce slashing a low drive across the face of goal, inches wide of creeping in at the far post.
Devlin was lucky to only see a yellow card for a late, high lunge on Ferguson on 67 minutes. Teddy Jenks then replaced Connor Barron for the Dons.
An Aberdeen free-kick found its way to Ferguson at the back post on 69 minutes, Atkinson flicking out a foot to bring him down for a penalty. For once, Ferguson proved fallible from the 12 yard mark, a hard, low drive into the bottom corner brilliantly saved by Gordon at full stretch.
Things went from bad to worse on 72 minutes as Hayes went down with a head injury following a mid-air collision. After lengthy treatment for the Irishman, the Dons made a double change, MacKenzie and Dylan McGeouch joining the fray in place of Hayes and Brown. Hearts took the opportunity of the break in the game to replace Devlin and Mackay-Steven with Haring and Ginnelly.
There was plenty of huffing a puffing from the visitors but nothing was really threatening the Hearts rearguard. Running the clock down, Halliday was brought on for Boyce for the hosts on 87 minutes.
Ferguson had another crack at Gordon's goal on 89 minutes, this time from a free-kick 30 yards out. He beat the wall, but not the goalkeeper who collected comfortably, too much the story of the evening.