Fans returned to Vicarage Road for the first time since February with enthusiasm and hope; they left feeling frustrated and deflated after Watford surrendered their unbeaten home record with a poor attacking display as Cardiff City returned to south Wales with a 1-0 victory.

The Hornets have struggled on their travels this season and, in many respects, this was an away performance at home as the hosts laboured and rarely put any sustained pressure on the Bluebirds goal.

There was some promise in the home side's early play but that soon dissipated and their opponents had looked the more likely to make the breakthrough before they did two minutes before the break when Kieffer Moore pounced after a corner had not been dealt with.

Watford’s approach play continued to be too pedestrian for the first half of the second period before some changes did finally bring some much-needed impetus. With a resolute and organised defence in front of him though, visiting keeper Alex Smithies was rarely extended as his side sealed a deserved success.

Vladimir Ivic made four changes from the side that again disappointed on its travels in Wednesday night’s drab goalless draw at Nottingham Forest.

William Troost-Ekong, Ben Wilmot, Tom Cleverley and Ken Sema all returned to the starting XI, taking the places of the suspended Nathaniel Chalobah, Craig Cathcart, Kiko Femenia and Domingos Quina.

The latter two were on a substitutes’ bench which also featured Etienne Capoue and the fit-again Will Hughes.

The Bluebirds came into the game off the back of consecutive victories and Neil Harris, unsurprisingly, opted to keep faith with the same starting line-up.

The presence of fans inside Vicarage Road for the first time in eight months brought a renewed sense of energy to the stadium and the Hornets sought to feed off that, making a positive start to the contest.

Sema raised the volume with one early run which threatened more than it ultimately delivered, before a long ball over the top almost put Troy Deeney in, but Cardiff keeper Smithies was alert to the danger and headed clear from the edge of his 18-yard box.

It took until the tenth minute for the first goal attempt to arrive when Joe Ralls curled a right-footed effort not too far wide of Ben Foster’s left-hand post.

But Watford went closer two minutes later when Jeremy Ngakia slipped a pass down the right side of the penalty area and Joao Pedro ran in behind to hit a low shot across and narrowly wide of the far post.

The towering presence of Moore headed a cross from the right wide at the other end as the opening quarter-of-an-hour continued to ebb and flow, with the visitors providing a good test as expected.

There was little in the way of goalmouth action again until the 26th minute when the Hornets built with promise and it needed a fine block from Curtis Nelson to prevent Deeney from getting on the end of an Ngakia cross. The hosts kept the attack alive though, but again more good Cardiff defending stopped Pedro having a chance from Ismaila Sarr’s delivery from the right.

It was then Watford’s turn to be on the back foot, as Deeney did well to head away after a corner had been nodded back into the danger zone by Sean Morrison, and then Troost-Ekong flung himself in front of Sheyi Ojo’s well-struck follow-up.

Cardiff went closer still in the 38th minute when Morrison rose highest to meet Ralls’ corner from the left, but the centre-half headed down and wide of the target.

Another corner followed soon, this time from the opposite side as Harry Wilson struck an inswinging delivery which an under-pressure Foster did well to punch clear.

Cardiff were knocking on the door and two minutes before the break their pressure told. Again it came from a corner, this time from the left, Watford failed to deal with the ball as it bounced in the area and Moore reacted quickest to sweep a left-footed finish past the helpless Foster.

The lead could have proved shortlived though. The Hornets were awarded a free-kick wide on the right which James Garner swung dangerously right across the six-yard box but nobody in yellow was able to get a touch as the visitors went into the break a goal to the good.

Ivic made a change at the start of the second half with a straight swap as Femenia replaced Ngakia, but it was Cardiff who had the first chance after the break when Sema did well at the far post to prevent Wilson from getting his head to as dangerous Joe Bennett cross from the left.

Soon after though, Watford’s approach play appeared to be too pedestrian, like it had been for much of the first half. However, Christian Kabasele had spotted Femenia’s run outside of him, sliding the ball down the side of the defence for the Spaniard to play a first-time cross but it was just too far ahead of Deeney.

The home side were in danger of being opened up again when the visitors broke down the right and Leandro Bacuna laid the ball inside to Moore, but his shot was blocked by a defender.

The temperature was raised a few notches when Cleverley and Ralls became involved in some pushing after the Cardiff man had made a hefty challenge, something which Ojo also did soon after on Garner for which he was penalised with a yellow card.

Ralls was to also see yellow for a body check on Sarr and Ivic took that opportunity to make a double change, bringing on Hughes and Quina for Cleverley and Sema.

Within moments of entering the fray, Quina had been picked out in the area by a superb pass over the top from Kabasele but a combination of Morrison and Smithies were able to block the substitute’s shot after he had brought the ball down.

Cardiff made their first change soon after as Junior Hoilett replaced Mark Harris, but the Hornets were now starting to finally build some attacking momentum as Smithies was forced to turn away a snap-shot from Femenia.

Soon after a Garner corner from the left picked out the head of Pedro but he was unable to divert it past the grateful Smithies, who was able to drop on the ball.

Nelson then diverted a dangerous Sarr cross over his own bar, when the ball could have gone anywhere, after the Senegal winger hit the after burners to reach a cross-field ball and then combining with Femenia.

Marlon Pack replaced Ojo with 14 minutes of normal time remaining before Wilmot made way for Stipe Perica.

Ralls shot high and wide on the angle before the home side finally mustered another opportunity when Hughes fired over from the right side of the area after a corner had dropped invitingly for him in space.

Cardiff had done their job well and their manager added to the Hornets’ frustration by making a late triple change, before referee Stephen Martin booked Perica for diving after deciding he had gone to ground far too easily when he sought to get on the end of a Deeney flick and was squeezed out.

Watford still had late chances to salvage something, but Quina struck a dreadful free-kick behind before a corner failed to reach its destination. The home side kept the ball alive though, with Sarr swinging over a deep cross from the left which picked out Perica at the far post but he was unable to direct his header on target – and with that went Watford’s chances of maintaining their unbeaten home record.

Watford: Foster; Ngakia (Femenia 46), Kabasele, Troost-Ekong, Wilmot (Perica 81); Sarr, Cleverley (Hughes 66), Garner, Sema (Quina 66); Deeney, Pedro. Subs not used: Bachmann, Capoue, Sierralta, Navarro, Dan Phillips.

Cardiff City: Smithies; Bacuna, Morrison, Nelson, Bennett; Wilson (Whyte 87), Vaulks, Ralls (Bamba 87), Ojo (Pack 76); Harris (Hoilett 69), Moore (Glatzel 87). Subs not used: Dil Phillips, Murphy, Benkovic, Cunningham.

Bookings: Ojo for a foul on Garner (59); Ralls for a foul on Sema (66); Perica for simulation (89).

Referee: Stephen Martin.