Paul Heffernan netted a hat-trick as Kilmarnock claimed their third straight win against Hearts this season.
Hearts had defender Darren Barr carried off following a clash of heads with team-mate Danny Wilson.
And Killie moved ahead before the break with Heffernan tapping home James Dayton's pass.
Heffernan converted William Gros' knock-down at a corner and got his third with a rebound shot after Borja Perez's effort had been saved.
The Ayrshire side move up to fifth in the Scottish Premier League, a point off Hibernian, while Hearts remain tenth.
Hearts, who have not beaten Kilmarnock since April 2010, were without the suspended Ryan Stevenson and captain Marius Zaliukas who will miss the rest of the season with an ankle ligament injury.
Barr came into the home defence, with Scott Robinson slotting into midfield.
Kilmarnock manager Kenny Sheils had goalkeeper Cammy Bell fit again, with James Fowler and Borja Perez also back in the starting XI.
And the visitors were offered a potential opening in the first minute.
Barr was short with a pass-back but Perez failed to control the ball and the chance was gone.
Further chances were few and far between, with both teams playing 4-5-1 formations and cancelling each other.
On 31 minutes Hearts were forced into a change when Wilson and Barr clashed heads.
Wilson was able to carry on after receiving stitches in a wound above his left eye but Barr was not as fortunate and, after a delay of six minutes, he was taken away on a stretcher.
Kilmarnock carved out the opener after 42 minutes.
William Gros crossed from the right and Dayton controlled the ball before firing back across goal for Heffernan to knock home his eighth goal of the season.
Hearts made a change at the break with John Sutton replacing Jason Holt and moving to a 4-4-2 formation.
And it almost had an immediate impact on the game as Bell saved well from Robinson and then punching away an effort from Jamie Walker.
With Hearts pushing more men forward, Kilmarnock found space on the break and Dayton forced Jamie MacDonald into a fine stop low to his left.
Killie doubled their lead after 65 minutes when Mo Sissoko knocked a header down to Heffernan on the edge of the six yard box and the striker was able to turn and fire the ball high into the roof of the net.
The Irishman completed his hat-trick with 19 minutes left.
Ross Barbour had a shot well saved by MacDonald but Heffernan was first to the rebound.