A shambolic start and a disappointing defensive display throughout ultimately cost Watford as rejuvenated Middlesbrough picked up their third victory in eight days with a 3-2 win at Vicarage Road.

Valerien Ismael responded to the 3-0 defeat at Leeds United by switching to a 3-4-1-2 formation but the Hornets looked completely lost in the opening stages as Boro – and two-goal Riley McGree in particular – were quick to capitalise on the big gaps in the midfield to go 2-0 up inside 12 minutes.

It looked like being a very long afternoon for the home side but neither side impressed defensively and a bad mistake from Dael Fry allowed Vakoun Bayo to give his side a desperately-needed foothold back in the contest.

The striker showed good composure to make it 2-1, but it deserted him when he was given a gilt-edged chance to equalise after rounding keeper Seny Dieng.

Ismael ditched the formation change at the interval, reverted to 4-3-3 and the home side were to be back on terms seven minutes after the restart when Wesley Hoedt crashed home a shot from a half-cleared corner.

But Watford were never able to able to dominate possession as they have often done this season – and lacked the quality on the ball when they did have it – and the visitors were to score what proved to be the winner when Matt Crooks slid through Daniel Bachmann to equalise.

Matheus Martins went closest to a leveller in injury time with a shot that clipped the bar, but Watford were never able to build up a sustained head of attacking steam as they fell to their fourth defeat of the season and slipped down to 20th in the table.

Ismael had made four alterations to his starting XI as well as switching formation.

Ryan Andrews, Tom Ince, Ismael Kone and Martins dropped to the bench and in came Jeremy Ngakia, Tom Dele-Bashiru, Ismael Kone and a second striker in Bayo.

Michael Carrick made seven changes for the midweek Carabao Cup victory at Bradford City, but his starting line-up showed just the one alteration from the team that secured a first league victory of the season by beating Southampton 2-1 last weekend with Paddy McNair replacing Darragh Lenihan, who was unwell.

The Hornets started in a 3-4-1-2 shape with Asprilla the most advanced of the midfielders behind the front two and the young Colombian looked lively early on, almost threading through Bayo with one pass.

But it was Boro who struck with their first real attack in the fifth minute – and it was far too simple in truth.

The ball was played infield from the left to Jonny Howson, who turned away from Tom Dele-Bashiru and advanced into space before slipping a pass through to McGree, who had found space between Ngakia and Ryan Porteous and fired a shot inside Daniel Bachmann’s near post, with the keeper badly exposed as he went in the opposite direction.

Watford tried to lift themselves from that poor start, Bayo glancing an Ngakia cross from the right down and wide of the far post.

Soon after though, the Hornets were to find themselves in even deeper trouble as Boro clinically capitalised on gaping holes in the home side’s ranks.

It started from a Dieng clearance that was helped on by McGree to his right where Crooks was able to run unchecked at the retreating Hornets rearguard before he played the ball back across to McGree, whose run forward into the D had not been tracked, and he calmly finished inside Bachmann’s right-hand post to make it 2-0 with just 12 minutes gone.

Watford desperately needed to get a foothold in the game – and they got it courtesy of some awful defending from Fry.

Porteous was the instigator with a cross-field ball that the Boro centre-half made a complete hash of trying to intercept, leaving Bayo with a clear run on goal and the striker kept his composure to slide a finish beyond Dieng to make it 2-1.

The visitors were still enjoying far too much space in the Hornets midfield, Isaiah Jones the next to try and benefit when he came inside off the right before firing high and wide of the target.

But in the 24th minute though, the Hornets really should have been level.

Asprilla played a lovely slide rule pass which Mileta Rajovic ran across, opening up the space in behind for Bayo to run onto. Although the striker’s first touch was a shade heavy as he looked to round Dieng, he still looked to have a formality finish into a largely unguarded net but this time his composure went missing as he lashed the ball high and wide of the target from the right side of the six-yard box.

The game was interrupted for a lengthy spell of treatment to Lewis O’Brien – who was subsequently replaced by Tommy Smith – but in between times Watford were almost caught out again when Howson clipped the ball into the area where the unmarked Crooks would have had a free header had the delivery been a bit lower.

Bayo headed wide from a deep Imran Louza cross following a short corner before Porteous received the game’s first yellow card for a foul on Howson.

The home side were looking to finish the opening half strongly as it moved into four additional minutes and they did have one further opportunity just before the break, with Rajovic heading over a Louza corner from the left, but the hosts went into the interval trailing.

Most of Watford’s substitutes were out warming up during the interval, but Martins soon appeared stripped and ready to come on, with Rajovic the player not to reappear for the second half.

It was soon clear from the kick off that the move to 3-5-2 had also been shelved, with the hosts reverting to the more tried and tested 4-3-3.

The Brazilian substitute was quickly into the action but it was Dele-Bashiru who had the first attempt, sending a dipping strike from 25 yards narrowly over.

The Hornets went much closer with their next effort though, Ngalkia sending over a deep cross from the right which Bayo met with a powerful downward header which Dieng did well to push behind.

But Watford did not have to wait much longer to get back on terms.

The resultant corner from the right was played short before it was crossed, but only half headed clear for a stretching Hoedt to meet it on the half-volley to send the ball arrowing back beyond Dieng into the far corner to make it 2-2.

The complexion of the game had changed and the momentum was now seemingly with the hosts, only for them to lose their way again for a spell with Porteous forced to put his body on the line twice, including from one almighty goalmouth scramble. Sierralta was also booked during this period for a late challenge on Jones.

Having battled back from two down though, the Hornets were to be undone again in the 64th minute.

Crooks - and not for the first time - was allowed too much time on the ball, and he threaded a pass in behind the defence for Coburn to run onto and beat Bachmann to make it 3-2.

Ismael responded by making a treble change, bringing on Edo Kayembe, Giorgi Chakvetadze and Ince for Sierralta, Louza and Asprilla.

Boro had a confident spell of possession thereafter but it was Watford who were the next to go close, Bayo switching the ball out to left to Martins who came inside before hitting a low right-footed shot which Dieng pushed behind.

There were Hornets hearts in mouths again in the 74th minute when Smith tried a left-footed shot which hit Hoedt’s head, completely wrong-footing Bachmann but, thankfully for the home side, the ball went wide of the near post.

Carrick made his second change with 12 minutes of normal time remaining as Marcus Forss came on for Jones, before McGree threatened again when he went on a good ruin to the edge of the area before dragging a shot well wide.

Ismael played his final hand by bringing on Rhys Healey in place of Dele-Bashiru, before Sam Greenwood came on for Crooks.

In between though, Ince opened up the left side of the Boro defence with a run but was unable to pick out a teammate with his cut back.

The addition of five extra minutes still gave the Hornets hope of a late equaliser and in the third of those Hoedt swept the ball out to the left where Martins, in trademark fashion, came back inside before hitting a right-footed curler which looked like it might dip inside the far corner, but clipped the bar as it went narrowly over.

And with that went Watford’s hopes as the final whistle was greeted by a short but audible boo from the Rookery, leaving the visitors able to celebrate a very good week’s work.

Watford: Bachmann; Porteous, Sierralta (Kayembe 64), Hoedt; Ngakia, Louza (Chakvetadze 64), Dele-Bashiru (Healey 85), Lewis; Asprilla (Ince 64); Rajovic (Martins 46), Bayo. Subs not used: Hamer, Kone, Pollock, Andrews.

Middlesbrough: Dieng; van den Berg, Fry, McNair, O’Brien (Smith 36); Howson, Hackney; Jones (Forss 78), Crooks (Greenwood 86), McGree; Coburn. Subs not used: Glover, Barlaser, Latte Lath, Rogers, Silvera, Engel.

Bookings: Porteous for a foul on Howson (40); Sierralta for a foul on Jones (55).

Referee: Oliver Langford.