The Canaries took less than two minutes to grab the initiative as poor defending from an Anthony McNamee corner allowed Holt to power a header goalwards. His effort hit the bar and rebounded kindly for Hoolahan to blast home from point-blank range.
Norwich went on to dominate the remainder of the game and should have doubled their advantage just before half-time when Holt played a one-two with Martin and rounded keeper Alex McCarthy, only to hit the side netting.
But Norwich duly wrapped up the points 20 minutes from the end courtesy of a another scrappy goal. This time McNamee's cross from the right was headed high up into the air by Terrell Forbes and when McCarthy missed his punch, Holt was on hand to convert from inside the six-yard box.
The points were made safe six minutes later when Holt set up Martin for his 20th goal of the season, with the striker's shot trickling into the back of the net after being only half-stopped by the Glovers keeper.