The two struggling sides showed the effort their managers will expect as they battled to avoid the drop, but worryingly for Tony Parkes and Brendan Rodgers the play was often devoid of craft, invention and cutting edge.
The first half started slowly then fizzled out altogether.
Blackpool carried the game to their opponents, but did little to suggest that they would penetrate a solid-looking Hornets backline.
Roy O'Donovan twice found space in the opening minutes of the first half to fashion chances but, on both occasions, failed to hit the target.
Gary Taylor-Fletcher had Blackpool's best effort, forcing Scott Loach to tip his goalbound volley over the crossbar.
For their part, Watford were content to rely on counter-attacks, but only once was Priskin given the opportunity to test Matt Gilks in the Seasiders goal.
The start of the second half saw a veritable frenzy of goalmouth action and David Vaughan nearly gave the Seasiders the lead with an angled shot which Loach did well to save.
On 54 minutes the Hornets claimed the lead, predictably enough from a set-piece. Jobi McAnuff's precision corner was met by the giant centre-back Mike Williamson.
Slack Blackpool marking allowed him to power his header into the roof of the net.
For ten minutes following the goal, Priskin and the mercurial Tommy Smith threatened to run the home defence ragged.
Only a deflection from the offside Priskin ruled out Ross Jenkins' 20-yard volley.
Blackpool introduced their talisman Brett Ormerod who inspired a late fightback but, despite testing the Watford defence several times, they were unable to find an equaliser.
Five minutes from time, Priskin latched on to McAnuff's throughball, drew the keeper and slotted home to make sure of all three points.