ANOTHER awayday victory for the Hornets, but despite the 3-0 scoreline this game was much tighter early on than may seem the case.
Watford took the lead in the first half through Paul Devlin's bullet header on 23 minutes, but after this were under the cosh for the rest of the half and into the second period.
An even period of play followed some early second half promise from the home side, but a stroke of luck put the Hornets two goals to the good when Ashley Young's curling free-kick eluded Steve Simonsen and found the bottom corner of the net from 25 yards out with 20 minutes gone in the half.
Czech winger Martin Kolar was a thorn in the side of the Hornets all afternoon and blew several chances to get the Potters back into the match, however he had to be sacrificed in the 68th minute when Simonsen was dismissed for tripping Young in the area.
King converted the penalty to put Watford 3-0 up and, with a man advantage, simply saw the game out comfortably.
Boothroyd made one change to the team from the Derby victory - returning to a 4-4-2 formation, he paired Young with King at the head of the team with Devlin taking Young's place on the right flank.
Stoke's starting XI was unchanged from their 3-1 win over Norwich, meaning there was no place for ex-Hornet Bruce Dyer in the team - he had to make do with a place on the bench.
The Hornets got off to a bright start with Devlin twice getting in crosses from the flank which Simonsen had to clear - Young then forced a corner from Marlon Broomes which was hurriedly cleared by the Potters.
On five minutes James Chambers' enterprising forward run allowed him to square back to King who took a touch and shot from 12 yards only to see it blocked by Carl Hoefkens.
A free-kick for Watford on the left of the box gave Young the chance to launch one into the danger area and only Mamady Sidibe's deflection denied Malky Mackay the opportunity to open his account from close range.
Lewis Buxton's right-wing cross took a deflection off Jordan Stewart on ten minutes and threatened to sneak in at the near post but Ben Foster, back at Stoke City for the first time since his move to Manchester United, saw the danger and smothered low down.
Seconds later he had to be alive to the threat of Sidibe who broke clear of the defenders but Mackay did enough to put off the former Gillingham striker, who scuffed an effort into the clutches of Foster.
After a quiet period of the game - during which the Hornets still maintained the better share of possession - a throw-in on the left was squared back to Anthony McNamee by King, and the Watford winger, who recently extended his contract at Vicarage Road for another two seasons, whipped in a superb curling cross to the edge of the six-yard box where Devlin arrived right on cue to head home with power past Simonsen in the Stoke goal.
The Potters were rocked but almost got back on level terms three minutes later - a spot of penalty area pinball and a half-cleared ball by Matthew Spring fell nicely to Buxton who took aim only to see his shot come back off the crossbar.
The Hornets tore back up the pitch with Chambers making ground on the right flank and, once he tricked his way into the area, was unlucky to see his effort ripple into the side netting.
Still the end-to-end action continued when Sidibe again broke free and placed a shot low to Foster's left - however the big goalie got down at full stretch to get both hands behind the ball.
And minutes later Martin Kolar could have levelled when Chambers' header dropped to the winger who took a touch and shot for the far corner, missing by inches from 15 yards.
Stoke were in the ascendancy and had the next chance on 35 minutes - Luke Chadwick's low ball from the right of the area fell to Kolar whose right-footed shot was on target but excellently blocked by Chambers who made up a lot of ground to get the tackle in.
Foster was at his best again with four minutes to go when Junior's fierce drive from the edge of the area looked destined for the bottom corner until the Hornets stopper got a firm left hand behind it, earning a round of applause from the Hornets fans behind the goal.
Kolar again got a shot off with time running out when Clarke Carlisle's desperate clearance from Sidibe's break into the area fell right to the Czech winger who placed a low right-footed effort to the bottom corner - Foster scrambled across and saw the ball clear the post in the last action of the half.
Into the second half and Kolar, again proving difficult to handle for the Hornets, smashed a shot at Foster which was parried away and then helped further on by Mackay.
On 52 minutes McNamee got space on the flank to cross for Young arriving in the box - Simonsen got there first but spilled the ball into the path of Young who just failed to make contact sliding in.
Three minutes later Dominic Blizzard's marauding run into the box almost yielded a chance for the Academy-grown midfielder to register his second for the Hornets but Broomes pulled off an excellent saving tackle in the area and the chance was lost.
Duberry's inadvisable challenge on Young on 65 minutes earned the former Leeds defender a yellow card - not the first time Young was chopped down in full-flight by the Potters defenders during this game. Young himself took the free-kick and, while aiming for the darting run of Carlisle towards the back post, completely deceived Simonsen and nestled the ball into the far corner with a curling effort from fully 25 yards.
Three minutes later a two-on-one break gave Young the chance to add a second - Carlisle's clearance was met by King who saw Young break to his left and lifted the ball over the last man to leave Young in the clear. The winger drove straight for goal but was upended by Simonsen who was dismissed for the challenge.
Stoke boss Johan Boskamp withdrew Kolar to allow sub keeper Ed De Goey to take to the nets and he immediately had to retrieve the ball from the back of the net following King's coolly-struck penalty, eventually taken in the 71st minute.
With a man advantage the Hornets maintained possession and Boothoryd opted to make a couple of substitutions, introducing Hameur Bouazza for Jordan Stewart and Al Bangura for Blizzard in the space of six minutes.
The final whistle blew on an excellent day away from home for the Hornets, nicely setting up the visit of Norwich City to Vicarage Road on Tuesday night - after a day like today, you won't want to miss it!
Line-ups
Watford: Foster; Stewart (Bouazza 76), Mackay, Carlisle (c), Chambers; McNamee, Blizzard (Bangura 82), Spring, Devlin (Doyley 65); Young, King. Subs not used: Chamberlain (GK), DeMerit.
Stoke: Simonsen, Hoefkens, Broomes, Duberry (c), Buxton, Brammer, Harper (Gallagher 59), Chadwick (Dyer 83), Kolar (De Goey 70), Junior, Sidibe. Subs not used: Henry, Taggart.
Referee: N Miller (Durham). Attendance: 14,565 (1,253 Hornets).
By James Frankland at The Britannia Stadium
