Pratley cut inside and spotted Van der Gun coming in off his wing on the right flank, dinking a cross into thepath of the onrushing Dutchman to head home from six yards out.
The same two players combined again to give Hull the lead with Koren advancing into space down the right flank and whipping over an inviting cross into thepath of Garcia, who headed home superbly.
The visitors could have doubled their advantage within four minutes of the break when Marc Twaddle headed Healy's cross into thepath of McLean, whose effort was blocked by Langfield.