Watford suffered their third consecutive defeat, their fifth straight loss on the road without scoring but are now all-but mathematically safe in the Premier League after being beaten 3-0 by resurgent champions Leicester City.

While the Hornets again fired blanks on their travels after Walter Mazzarri opted to drop Troy Deeney to the bench, the Foxes won the points after making the most of bad decisions and mistakes at the back.

The game, arguably, should have been goalless at the break, but having survived an earlier scare when Adrian Mariappa turned a Jamie Vardy centre against his own woodwork after Stefano Okaka had switched off at a free-kick, Watford didn’t survive a second lapse from a set piece.

This time they switched off at a corner and when the ball was played towards the six-yard box Etienne Capoue tried to take a touch, rather than put his foot through it, and Wilfred Ndidi smashed in the opportunity.

There had otherwise been some encouraging aspects about Watford’s approach play in the first half but too often it was let down by the quality of the final ball.

But it was to be another defensive lapse that was punished 13 minutes after the restart, this time from Mariappa, as Riyad Mahrez doubled the Foxes’ lead.

The home side could have gone on to score more as their opponents looked like their had thrown in the towel for a spell. They then roused themselves again, but were only able to test Kasper Schmeichel from long range, before there was a bright moment for one Watford youngster when Dion Pereira became the latest Academy product to make his first-team debut.

But the Foxes were to add a third in injury time through Marc Albrighton, leading to boos at the final whistle from the visiting faithful who had sporadically chanted the name of former head coach Quique Sanchez Flores throughout the second half.

Those boos then turned to loud cheers for Pereira, but news of Hull’s 2-0 defeat at home to Sunderland means the Tigers cannot overtake the Hornets in the table unless there is a significant swing in goal difference - and that will only become a factor if Mazzarri's men lose all three of their remaining games and Hull claim a maximum of six points from their final two fixtures. 

The Hornets boss made two changes from the team that lost 1-0 to Liverpool; one of which was enforced, the other a big call.

Christian Kabasele kept his place in the back three having replaced the injured Miguel Britos on Monday, but the more eye-catching alteration saw Deeney drop to the bench as Stefano Okaka got the nod to start up front.

With captain Wes Morgan still injured, Craig Shakespeare kept faith with the same side that claimed a first win in six games in all competitions last time out with a 1-0 victory at West Bromwich Albion.

The Hornets had the first possibility to create an opening in the first minute when Okaka advanced before feeding Daryl Janmaat to the left of the penalty area, but the Dutchman was unable to pick out a white shirt with his cross.

It didn’t take long for the Foxes to get on the front foot though, with the head of Sebastian Prodl forced into early action to repel crosses from Marc Albrighton and Mahrez from either flank. The hosts also won a couple of early corners which Watford were equal to defensively.

The game continued to be something of a battle with both sides fighting for the right to play, but the Hornets had a chance in the 13th minute when a loose throw out from Kasper Schmeichel was intercepted by Nordin Amrabat. He initially shaped to cross but with only Okaka in the box, knocked the ball back inside to Abdoulaye Doucoure, who in turn fed it infield to Tom Cleverley. The midfielder, who was making his 50th Hornets appearance, was in a good position to shoot on the edge of the area, but fired wide of Schmeichel’s left-hand post.

This signalled the start of a promising spell for the visitors though, who began to get into some useful situations, but were let down by the quality of the final ball.

But in the 18th minute, Watford were fortunate not to go behind after one player was caught napping, but his teammate was very alert to the subsequent impending threat.

The visitors had a free-kick to defend after Cleverley fouled Mahrez, but Okaka briefly switched off as the Algerian took it, allowing Vardy to pull off into space on the right side of the penalty area as the set piece was rolled down the side of the wall. The England striker duly squared it across the six-yard box and Shinji Okazaki would have had a formality finish were it not for the lunging intervention of Mariappa, who deserved the luck of seeing his clearance rebound to safety off the post.

Another potential own goal situation arose when Christian Fuchs whipped in a dangerous cross from the left and Kabasele launched himself at it facing his own goal, back the diving Heurelho Gomes was able to tip away the header.

The Brazilian’s opposite number was forced into his first meaningful save of the match, blocking an Okaka shot on the turn with his legs at the near post after the striker had received a pass from M’Baye Niang.

Schmeichel was forced into action again in the 36th minute, diving to his right to push away a stinging drive from Cleverley after a Janmaat cross from the left had broken for him off Wilfred Ndidi.

But the visitors had a dangerous situation of their own soon after when Prodl committed a foul right of centre around 25 yards out. It was no surprise that Mahrez took the free-kick but the wall, or rather Okaka’s header, did its job and the ball went behind for a corner. But the Hornets’ reprieve was to be short lived.

The visitors didn’t react to the initial set piece as it was played short to Danny Drinkwater, he clipped the ball into the danger zone from the right side of the area, Capoue tried to take a touch instead of clearing first time and Ndidi gratefully gobbled up the loose ball, blasting it past Gomes to make it 1-0.

Leicester could have doubled their lead soon after when Mahrez twisted and turned on the right side of the area before hitting a shot that struck Janmaat and looped narrowly over the bar.

The Hornets started the second period on the front foot, but it was Gomes who was the first keeper called into action, diving to his left to keep out a low strike from Vardy after the Leicester striker had run in behind to take an Okazaki pass in his stride.

With the away fans, pointedly, breaking into a chant for former boss Flores, Watford carved out a good opening when Doucoure fed Amrabat on the right, he stood up a good cross but an under-pressure Okaka headed over the top.

The failure to take opportunities was emphasised in the 58th minute when Leicester doubled their lead.

A long ball forward should have been dealt with by Mariappa, but he miscontrolled on the right side of his penalty area and Mahrez was onto it in a flash, closing in on goal before rolling the finish between Gomes’ legs as Prodl desperately made a challenge.

Shakespeare was the first manager to make a change four minutes later as Okazaki was replaced by Islam Slimani before Andy King came on for Drinkwater and Capoue made way for Deeney, who came on to make his 300th appearance for the Hornets in all competitions.

But the traffic continued to be mainly towards the Hornets goal and Gomes had to make another smart save to thwart Vardy from the left side of the 18-yard box after the striker had received a Slimani pass and wrong-footed Mariappa with ease.

Watford were increasingly getting carved apart with too much ease and Slimani was the next to have a chance, shooting over on the turn after being set up by Mahrez.

Fuchs then curled a 25-yard free-kick narrowly over the top after Deeney had committed a foul, before Mazzarri made his second change as Camilo Zuniga replaced Kabasele.

The Hornets were finally able to gain something of a respite around the 75-minute mark and twice made Schmeichel work, as he first dived to his left to keep out a Niang curler and then held a low Cleverley strike.

The former Everton midfielder had even better effort soon after, forcing the Leicester keeper to tip over his strike from the edge of the area after Amrabat had skipped clear on the right and pulled the ball back.

Demari Gray came on for the final 12 minutes of normal time in place of Mahrez, but then came a moment to remember for a young Watford player as Pereira became the latest Academy graduate to make his first-team debut in place of Niang.

And the winger was quickly into the action, whipping in a lovely left-footed cross from the right which Okaka flicked and Deeney stabbed wide, although he was offside.

Watford didn’t give up in their search for a goal but it was the Foxes who had the last laugh when they countered and Vardy set up Albrighton, who smashed in a low finish off Gomes’ near post.

Leicester City: Schmeichel; Simpson, Benalouane, Huth, Fuchs; Mahrez (Gray 78), Drinkwater (King 67), Ndidi, Albrighton; Okazaki (Slimani 62); Vardy. Not used: Zieler, Chilwell, Musa, Amartey.

Watford: Gomes; Kabasele (Zuniga 72), Prodl, Mariappa; Amrabat, Capoue (Deeney 67), Doucoure, Cleverley, Janmaat; Okaka, Niang (Pereira 83). Not used: Pantilimon, Success, Behrami, Eleftheriou.

Bookings: None.

Attendance: 31,628.

Bookings: Roger East.