By the time the full-time whistle was blown, it felt long ago that the outstanding Jamie McGrath had somehow managed to raise the noise level when he cushioned in an early opener from Nicky Cadden’s cross from the left.
A first-half injury for Cadden then meant McGrath had to shift from midfield to left-wing back, and it was from that side the Hibs man provided the cross for substitute Josh Campbell to glance in an excellent 45th-minute header to the far post.
Hearts did not manage a shot on target in the first period but passed up a glaring chance to level when Shankland directed a header just wide of the far post.
Losing a second goal so close to the break was a damaging blow for McInnes’ rattled side, who were three down minutes after the interval when Stuart Findlay’s poor clearance allowed Kieron Bowie to drive forward and thump in a third.
The Gorgie visitors caused serious nerves among the home support, though, turning the screw in the final stages as Shankland headed in a wicked ball from Alexandros Kyziridis, who had two earlier efforts saved.
Sallinger then parried another Kyziridis strike straight into the path of Devlin to finish on the rebound, but Hibs managed to hold on to their advantage in a wild conclusion.
David Gray’s men stay fifth but move to within two points of third-placed Motherwell.