It was a tale of two penalties as Matej Vydra’s spot-kick earned Watford three points before Nile Ranger hit the post with his.
The Czech striker made no mistake from 12 yards to grab the game’s only goal, and give the Hornets their first win at Bloomfield Road since 2009, after Tony McMahon had brought down Lloyd Dyer on 66 minutes
The first hald could have seen either side go into the break with a lead, though only Joe Lewis’ heroics saved the home side from going in behind.
The game evened up after the break, with both sides creating chances and each winning a penalty, though Nile Ranger failed to do what Vydra could from 12 yards.
Apart from McMahon’s third-minute effort from 25 yards, which Heurelho Gomes had to tip round the post, Blackpool rarely threatened in the first half-hour.
In a moment that typified their season so far, the home side were nearly behind after three minutes as Peter Clarke’s clearance cannoned off Joan Oriol towards his own net, forcing Lewis into a reaction save.
After 23 minutes Lewis McGugan earned a corner, from which Joel Ekstrand should have scored - rising to meet a free header but denied by the crossbar.
The best chance of the half came in the 42nd minute as Watford countered a Blackpool corner but Lewis denied Ikechi Anya with a fantastic save.
Blackpool could have snatched the lead just before the break as John Lundstram’s free-kick from deep found Donervon Daniels, though he could only direct his header straight at Gomes.
Five minutes into the second half Ishmael Miller headed on McMahon’s long ball to put strike partner Francois Zoko through, but the onrushing Gomes was there to keep the scores level.
Troy Deeney should have put the Hornets ahead on 57 minutes after bursting through a packed Blackpool box but he put his shot straight at Lewis.
The breakthrough finally came in the 66th minute as Dyer, who had replaced McGugan eight minutes earlier, turned McMahon in the box, with the Blackpool skipper bringing him down to allow Vydra to convert low to Lewis’ right.
The home side were galvanised and could have equalised four minutes later as Miller met a corner and headed beyond the stranded Gomes, only for Deeney to save with his chest and hook the ball off the line.
Watford were lucky to hold onto their lead when Daniel Pudil was adjudged to have brought down substitute Ranger, but the former Newcastle United man’s penalty struck the inside of the post before rebounding clear.
Miller had a chance to equalise at the death from Lundstram’s free-kick, but his header was saved well by Gomes, who earned Watford a win.