Hamilton Academical 2 Heart of Midlothian 0
Simon Mensing was the hero, ending a run of 19 games against the Tynecastle side without a win in any competition, stretching back to season 1979-80.
It was merited too, as Hamilton were simply the better side. Hearts never really got going until they were 2-0 down, and didn't cause home keeper Tomas Cerny any particular trouble throughout the 90 minutes.
Hamilton are breaking records in the SPL this season, recording their fifth successive home win, and they've also notched up five straight wins in January as well, including a narrow victory over Ross County in the Homecoming Scottish Cup.
More importantly for Billy Reid's men, the win over Hearts has taken them further away from the relegation pack.
Hamilton started well and within the opening six minutes Andy Driver had to clear from James McCarthy, before Brian Easton's corner from the right was headed away from Martin Canning, who was lurking with intent at the back post.
But Accies took the lead in 12 minutes when Easton played a short corner to James McArthur on the right, took the return, and his cross was headed in by Mensing at the back post.
Hearts nearly levelled five minutes later when David Obua cut inside from the right and sent a low effort that deceived Cerny and crashed off the base of the left post.
Bruno Aguiar's cross caused problems for Hamilton in the 31st minute, with Michael Stewart's hooked volley blocked by Cerny before it was cleared by captain Alex Neil.
Obua was looking dangerous and his dipping shot looked to be heading for the back of the net until Cerny superbly tipped it over.
Hamilton started the second half well and Mark McLaughlin met an Easton free-kick with a powerful header, only to see keeper Jamie MacDonald punch it off the line.
But Hamilton wrapped up the points in the 52nd minute when McCarthy made his way into the box only to be dragged off the ball by defender Robbie Neilson, with referee Eddie Smith immediately pointing to the spot.
Mensing stepped up to confidently bury the penalty into the bottom right corner past the despairing dive of MacDonald for his fourth goal of the season.
Hearts threatened with Driver and Stewart having efforts saved by Cerny, before Accies striker Richard Offiong headed an Easton corner inches past the left post.
And Hamilton could have stretched their lead when subs Joel Thomas and Derek Lyle combined, with the latter's looping 80th-minute header being well-saved.