The Cottagers’ season of struggle reached its inevitable conclusion at Vicarage Road, where fine goals from Abdoulaye Doucoure, Will Hughes, Troy Deeney and Kiko Femenia ensured a ninth successive defeat.
Ryan Babel’s finish had briefly given the visitors hope of at least delaying their demise, but it was not to be.
Following 33 league fixtures they have a disappointing total of 17 points, which leaves them 16 from safety.
With minus-46 they also have the division’s worst goal difference, having already sacked two managers in Slavisa Jokanovic and Claudio Ranieri, and all after their net spend of £106million over the past two transfer windows represented the third highest in the league.
It took until midway through the first half, perhaps owing to the pressure Fulham felt and the likelihood Watford considered Sunday’s FA Cup semi-final against Wolves their priority, for play to become stretched but it did so quickly and convincingly.
The fit-again Aleksandar Mitrovic had just had a shot routinely saved by Ben Foster when Femenia broke down the right wing and delivered a dangerous cross towards Deeney, who should at least have tested Sergio Rico with a diving header.
Doucoure then scored his second in two games when receiving possession from Hughes towards the edge of the area, carrying it just inside as the visitors’ defence backed off, and then striking low, inside the left post and beyond the diving Rico’s reach.
If Fulham were expected to then struggle in the same way they have on so many occasions this season, they instead briefly demonstrated some of the resilience that caretaker manager Scott Parker — whose playing career owed much to that very quality — has tried to instil in them.
In possession in the 33rd minute, the again-lively Ryan Sessegnon played a fine through-ball to Babel that took out Adrian Mariappa and left the forward with only Foster to round, which he did before calmly finishing into the back of the net.
The visitors quickly again found themselves under pressure in the second half, with both Jose Holebas and influential substitute Andre Gray threatening, but it took a superb strike for Watford’s lead to be restored.
When Maxime Le Marchand attempted to head clear from a 63rd-minute corner, he did so only as far as inside the edge of the area, from where the composed Hughes calmly strode forward under the high ball to brilliantly and powerfully volley towards the top right corner and in.
Amid further poor defending in the 69th minute, Gray raced clear into Fulham’s penalty area and squared to Deeney who put victory beyond doubt by finishing with conviction into the bottom right corner.
Gray then furthered his claims to start on Sunday at Wembley, this time providing a similar assist for Femenia, who from narrowly further out than Deeney also finished first time, but with the side of his right foot and towards the top left corner, lifting the hosts to eighth.