Buoyed by a 5-0 hammering of St Mirren at the weekend, the Jambos started on the front foot with Josh McPake looking particularly threatening on the left wing.
Despite the bright beginning to the game, they only had a speculative Malachi Fagan-Walcott shot from distance to show for it.
The visitors started to grow into the contest later in the first half, with Prince Amoako Junior proving particularly tricky and coming closest to grabbing the opener, as he cracked the post with a driven 22nd-minute shot that had Beau Reus well-beaten.
That appeared to spark some life back into the home side, and they were able to find a clinical edge to break the deadlock just after the half-hour mark.
A corner wasn’t properly cleared by Nordsjaelland and Jamie McCart played the ball into the six-yard box, where it was prodded home by Oisin McEntee to the delight of the Tynecastle crowd.
McPake then almost doubled the lead just before half-time, but was denied by a superb fingertip save from Andreas Hansen.
The hosts were almost gifted a second shortly after the interval when Juho Lahteenmaki miskicked and allowed McPake through on goal, but he could only drag his left-footed effort wide of the target.
Instead of pressing on to make the points safe, the hosts opted to go ultra-defensive in the final ten minutes, and they paid the price in the 86th minute.
Substitute Nicklas Rojkjaer was given time on the edge of the box to size up a shot, and a wicked deflection left Reus with no chance as the ball nestled into the back of the net.
Having failed to progress past the league phase in their last four attempts in European competition, the point will likely suit Nordsjaelland more, with the Danish side suffering defeat in their opening away game on all four occasions.
Hearts, on the other hand, will rue the chance to put three points on the board, especially with a daunting trip to Trabzonspor coming next.
Flashscore Man of the Match: Andreas Hansen (Nordsjaelland)