Watford have been knocked out of the FA Cup following a 1-0 fourth round defeat at Millwall – and Walter Mazzarri’s men can have absolutely no complaints about their fate.

Steve Morison’s goal caused the shock for the League One side with six minutes of normal time remaining as the Hornets got what they deserved after producing an abysmal display in front of the live TV cameras.

Watford could have been behind inside the opening 20 seconds and that set the tone for a performance that was mediocre at its peak, with many passages of play for which more negative adjectives would be more apt.

The Hornets’ play was frequently flat and lacking in urgency, their approach work was ponderous with the ball often passed slowly sideways or backwards rather than forwards and there was once again a lack of creativity.

Some may point to the fact that Walter Mazzarri made seven changes but it was still not unreasonable to expect the Hornets to produce a better calibre of display against a League One side who, although they were clearly up for the game, were limited in their approach.

One adjustment was always going to have to be made to Mazzarri’s side with Jose Holebas suspended, as Younes Kaboul, Miguel Britos, Abdoulaye Doucoure and Stefano Okaka were the four to keep their places from last weekend’s 2-2 draw at Bournemouth.

Adrian Mariappa made his first appearance of the season and second Hornets ‘debut’, 11-and-a-half years after his first, while Ben Watson came in for just his second start of the campaign and was made captain for the game. But there was no place in the matchday 18 for Odion Ighalo with his time at Vicarage Road expected to come to an end before the transfer window closes.

Neither of the Hornets’ two new signings featured, with Mauro Zarate suspended while M’Baye Niang was still awaiting international clearance.

The team selection was much more straightforward for Millwall as Neil Harris named the same starting XI that drew 1-1 with Bradford City last time out.

The match got off to predictably fast start but having looked to attack, the visitors were very fortunate not to be behind inside 20 seconds when a long clearance out of defence set Morison away on the right and his cross on the run picked out Lee Gregory, whose cushioned half-volley hit the crossbar with Costel Pantilimon well beaten.

The Lions looked by far the more switched on of the two sides in the opening stages and Pantilimon was forced into action again to tip over a deflected Tony Craig strike. Then from the resultant corner on the left, Jake Cooper was able to rise unchallenged around 12 yards out but he couldn’t direct his header on target.

Watford’s start to the game had very few redeeming features but they did start to get the ball down and pass it around as the 15-minute mark ticked by and this helped bring about their first attempt of the afternoon; Adlene Guedioura dragging a shot well wide from 20 yards.

The visitors’ play continued to be largely lethargic and uninspired but they went close to talking the lead in the 25th minute when Guedioura whipped in a free-kick from wide on the left and the ball deflected off a Millwall head and behind after clipping Jordan Archer’s left-hand post.

The Lions’ early impetus had now been quelled and Watford had a degree of control over proceedings and ten minutes before the break they had another opportunity when Jerome Sinclair and Doucoure got in each other’s way in the Millwall box, but the former Liverpool man managed to open up a shooting opportunity, only to kick his own foot as he went to strike the ball.

That was messy but what followed moments after was tantamount to farcical as Mariappa tried to let a pass run for Pantilimon, only for a ridiculous mix up to happen as Gregory almost nipped in and the desperate Hornets keeper dropped on the ball. However, the Romanian stopper injured his leg in making the save and it quickly became apparent he would be unable to carry on, meaning Heurelho Gomes had to take his place three minutes before the interval.

The lengthy delay meant the fourth official signalled six minutes of injury time and in the second of those Gomes had to make an instinctive stop high to his left to keep out a Gregory volley from Morison’s knock down. There was more danger when the resultant corner from the right was flicked on and Guedioura had to head clear from almost beneath his own crossbar as the Lions finished the opening half the stronger.

And that pattern continued immediately after the restart as a ball into the box was nodded back at the far post and it sat up nicely for Gregory, but he got underneath his attempted left-footed finish and fired high and wide.

The Hornets’ first opportunity after the break when Brice Dja Djedje played in a low cross from the right but the ball was just too far in front of Okaka for him to claim a touch as Archer safely gathered.

Another crossing chance came soon after, this time from the opposite flank when Brandon Mason’s delivery was just too high for Okaka and the ball drifted not too far wide of the far post.

But the visitors were to suffer another injury blow approaching the 55th minute when Dja Djedje was caught late but although a stretcher was called onto the pitch, it ultimately wasn’t required and neither was a substitution, meaning Daryl Janmaat was able to sit down again after being readied to come on.

Prior to that incident, the Hornets had good grounds to appeal for a penalty as Okaka was clearly hauled back as he tried to get on the end of another delivery.

Dja Djedje did make way for Janmaat after 68 minutes but the visitors were still finding it hard to create much in an attacking sense from open play.

The visitors then did start to play with greater urgency as they tried to find a winning goal, but with Archer still largely untested Mazzarri decided to bring on Troy Deeney with 13 minutes left in place of Sinclair.

It was then the Lions turn to have the better of the exchanges for a spell, with Gomes choosing to punch away a Morison shot from the edge of the 18-yard box. And that promising spell was to be deservedly rewarded with six minutes to go when substitute Shane Ferguson got the ball on the left and his deep cross was met by Morison, who hammered a first-time right-footed shot inside Gomes’ left-hand post to make it 1-0.

The hosts had the ball in the net for a second time from a corner a couple of minutes later but the ‘goal’ was disallowed by referee Martin Atkinson before Watford finally mustered an attempt on target when Watson’s header into the danger zone was flicked goal-ward by Deeney, but Archer was not unduly troubled.

Six minutes of injury time afforded the visitors hope of still salvaging an undeserved replay but they ultimately got what they deserved – nothing.

Millwall: Archer; Cummings, Webster, Cooper, Craig; Onyedinma (Wallace 71), Thompson, Williams, O’Brien (Ferguson 71); Gregory, Morison. Not used: King, Martin, Worrall, Romeo, Abdou.

Watford: Pantilimon (Gomes 42); Kaboul, Mariappa, Britos; Dja Djedje (Janmaat 68), Doucoure, Guedioura, Watson, Mason; Okaka, Sinclair (Deeney 77). Not used: Prodl, Cleverley, Cathcart, Capoue.

Bookings: Britos for a foul on Onyedinma (66); Mason for a foul on Wallace (81); Doucoure for a foul on Thompson (90); Wallace for a foul (90).

Referee: Martin Atkinson.