That seemed to spark Watford into life and they got themselves back into the game in the 66th minute when Faraoni headed home an Almen Abdi cross from close range. It looked as though the game was over minutes later when Karacan restored the two-goal advantage with a neat finish on 70 minutes.
But Watford were not done as once again they got themselves back into the game - this time from the penalty spot.
Guthrie pulled Fabbrini down in the area and referee Mike Jones had no hesitation in pointing to the spot.
Deeney stepped up to coolly slot the ball past McCarthy and, with stoppage time fast approaching, Fabbrini prodded the ball past McCarthy from close range to rescue a point.
More top news
Thursday's weather for the east of the region
Thursday's weather for the west of the region
Thursday morning's weather for the east of the region