But their mood lightened three minutes later when Ivan Toney scored from the spot at the other end for his 16th goal of the season – and it brightened further when the hosts seemed to have a late goal mistakenly ruled out.

The result moved Watford up to third and kept Brentford, who last lost on October 24 and have not beaten the Hornets since 1977, in sixth.

The first real chance was Watford's on the quarter-hour mark as Sarr swivelled in the box but Bees goalkeeper David Raya was behind his low 12-yard effort.

The Bees retaliated with Toney stretching to head Bryan Mbeumo's cross just wide of a post as Watford watched, and soon after Mbeumo burst into the box but could not keep his shot down.

Watford were relieved to come through that unscathed but looked unsettled, with the 2,000 fans present for the last time for the foreseeable future voicing their frustration.

Toney had another go, this time from distance, but his shot was always rising and cleared the crossbar.

The former Peterborough striker was undeterred however and saw his next effort, from just inside the box in the 37th minute, float over Foster but bounce back off the far upright.

Toney decided to be unselfish as he burst into the box four minutes before the break by trying to play Josh Dasilva in. His team-mate had been pushed too wide to shoot however so attempted to return the favour, and Toney ended up poking the ball wide.

Watford began the second period strongly, with Tom Cleverley firing an early chance wide and Ken Sema getting past two men to set up James Garner, who lost his footing at the vital moment.

Raya saved from Deeney before referee Linington and his officials made their most controversial call in the 56th minute. Sarr chased Jeremy Ngakia's forward pass and went down in the box as Pinnock made contact.

Linington consulted a linesman and awarded a penalty before showing the defender a red card, to the fury of Bees manager Thomas Frank and his players, who felt Sarr had been offside, a theory television replays would have confirmed to VAR had it been in operation.

Deeney made no mistake from the spot for his third goal in as many matches.

Within five minutes Linington awarded another at the other end when Mathias Jensen's shot hit Christian Kabasele on one of two raised arms. Toney nonchalantly slotted home from 12 yards.

Substitute Stipe Perica had a header ruled out for Watford in the 82nd minute for offside – a call the officials also appeared to have got wrong as the striker was level with the last defender.