Gus Poyet went head to head with his former Chelsea colleague Gianfranco Zola and it was the Albion man who emerged victorious following a dogged performance by his side.
A second-half Craig Mackail-Smith penalty was all that separated the sides as in-form Albion made it four wins on the bounce, but they were made to work hard for the victory.
Poyet's side had come into the game buoyant on the back of a 3-0 win against Sheffield Wednesday but it was the hosts - looking to respond following three successive defeats - who started the brightest.
Fernando Forestieri carved out the game's first opening with a 20-yard shot that took a double deflection. It left Tomasz Kuszczak completely wrong-footed but fortunately for the Albion keeper it drifted wide for a corner.
The Hornets also had the ball in the net when Almen Abdi converted from close range, but the midfielder was clearly standing in an offside position when he converted.
Marco Cassetti was fortunate to stay on the pitch for the Hornets in the 18th minute following a late lunge on Liam Bridcutt but it was the hosts who kept surging forward, with Abdi trying his luck from distance.
Albion had to wait until the 24th minutes to create their first real effort when a surging run and cross by Will Buckley - returning to his former club - was met at the near post by Mackail-Smith, but his deft touch went wide.
Another rapid run and cross by Buckley soon after eluded everyone bar Dean Hammond at the far post, but his low effort was kept out by former Arsenal keeper Manuel Almunia.
Seagulls then stepped up the pace, with Buckley again sending in another dangerous cross which Hammond this time uncharacteristically drilled over.
It was one-way traffic, with Mackail-Smith miscontrolling a teasing ball into the box by Wayne Bridge with the goal gaping, while Gary Dicker saw a close-range effort smothered by Almunia.
Albion started the second half again on the front foot and took the lead on 50 minutes when Pudil brought down Mackail-Smith in the box. In Ashley Barnes's absence, the in-form striker dusted himself down to clinically dispatch the spot kick - his sixth goal in four games.
Watford responded when Forestieri's shot from the edge of the box hit Kuszczak's bar but it was Albion who could have been two up on 62 minutes when Bridcutt played in Mackail-Smith. The striker raced in on goal but his effort flew narrowly over Almunia's bar.
It was turning into a frustrating night for the lively Hammond, who again found himself in a great position having met sub Barnes's cross, but his shot was comfortably claimed by the Hornets keeper.
A one goal advantage is often a precarious scoreline and Watford threw everything at Albion in the closing stages.
Abdi flashed a header wide for the hosts while Pudil looped a header over the bar.
Jonathan Hogg had claims for a penalty waved away in the 81st minute when he fell under the challenge of Bridcutt, while Nathaniel Chalobah had a less hopeful shout for a spot-kick waved away by referee Drysdale minutes later.
But a solid rearguard action, led by Gordon Greer, ensured Albion headed home with all three points.
Watford: (4-3-3) Almunia; Cassetti (Doyley 46), Neuton, Nosworthy, Pudil; Yeates, Hogg, Abdi; Vydra, Iwelumo (Beleck 78), Forestieri (Chalobah 73). Subs not used: Bond (GK), Forsyth, Smith, Hoban.
Albion: (4-3-3) Kuszczak; Bruno (Calderon 90+1), Greer, El-Abd, Bridge; Bridcutt, Dicker, Hammond; Buckley, Mackail-Smith (Dobbie 73), Orlandi (Barnes 60). Subs not used: Ankergren (GK), Dunk, Lopez, Harley.
Referee: Darren Drysdale
Attendance: 11,894 (1,934 Albion)
Yellow cards: Neuton, Cassetti, Nosworthy, Pudil (Watford); Bridcutt, Dobbie, Barnes (Albion)