It was a workmanlike rather than a particularly eye-catching victory but Watford did what was needed and beat Swansea City 1-0 to reach the 40-point mark and end any lingering doubts about securing their Premier League status.
The only goal of the game came shortly before half-time when Etienne Capoue capitalised on a bad mistake by Alfie Mawson and scored at the second attempt. But while the lack of a second goal afforded the relegation-threatened Swans continued hope of getting something from the game, they lacked the quality in front of goal to put Heurelho Gomes’ goal under threat for sustained periods.
That said, the Hornets could have made the afternoon more comfortable for themselves in a game they were in relative control of for periods, but not to the extent where they were able to relax and play in a fluid attacking manner.
But the celebrations of Mazzarri at the final whistle demonstrated what this victory meant, embracing his coaching staff before turning to the Elton John Stand and waving and applauding before diasappearing down the tunnel.
The Hornets boss made three changes to the side that was heavily beaten to an extent as injury again forced his hand to an extent with Craig Cathcart ruled out with a knee injury. On the flip side though, Sebastian Prodl was fit to take his place and Valon Behrami was available again to take his place on the bench.
The other two changes were predictable to a degree, with Capoue and Deeney returning to the starting line-up at the expense of Isaac Success and Steafno Okaka.
Swansea came into the game on the back of a five-match run without a win and five successive away defeats and boss Paul Clement opted to shuffle his pack, making four changes from the team that lost 1-0 at West Ham United last weekend.
One of these was enforced as former Hornets loanee Jack Cork was injured, while Jordan Ayew, Wayne Routledge and Watford-born Tom Carroll all dropped to the bench. Their places were taken by Jay Fulton, Ki Sung-Yeung, Luciano Narsingh and the fit-again Fernando Llorente.
The Hornets started confidently and had the first opening in the third minute when Abdoulaye Doucoure swept the ball out to Nordin Amrabat on the right. With the assistance of a favourable bounce and Daryl Janmaat helping out, the Moroccan international got the better of a tussle with Martin Olsson but his cross was headed clear.
The Swans were looking edgy at the back in the opening minutes, but it was the visitors who forced Gomes into the first save of the afternoon when he had to parry a rising angle drive from Gylfi Sigurdsson around his near post after the hosts hadn’t really dealt with a ball into their 18-yard box from the right.
Watford were nearly caught out again in the 14th minute when, after Deeney had fouled Leroy Fer, Gomes tried to punch clear Sigurdsson’s free-kick, bit mistimed it and the ball spun up in the air towards the far post where Federico Fernandez’s attempted header back across goal landed on the roof of the net.
M’Baye Niang had been relatively quiet in the opening stages but when Deeney flicked on Gomes’ goalkick the AC Milan came in off the left flank, but didn’t really get hold of his long-distance effort and Lukasz Fabianski dropped to his right to save.
Amrabat pulled a better struck effort from a similar range wide soon after before Fabianski had to race from his line to clear as Capoue’s through ball almost put Deeney in on goal.
The hosts had a good chance in the 23rd minute when Doucoure latched on to a loose pass and surged forward before feeding Niang, who was tripped by Fernandez on the very edge of the 18-yard box as he sought to check onto his left foot. Niang took the free-kick himself and kept his right-footed strike low, but the Swansea keeper got down well to hold.
The former Arsenal stopper had to make a better save soon after though, arcing his back to push over a Deeney effort on the stretch as he just got ahead of Kyle Naughton to meet Janmaat’s dug out cross from the right; the ex-Newcastle United man first beating Sigurdsson to the ball and then nicking it past Mawson.
The resultant corner saw Mazzarri’s men go close again when Prodl met the delivery from the right with a firm header, but this was deflected wide.
The Hornets were having a useful spell but they were stretched in the 30th minute when Llorente’s knock down enabled Narsingh to use his pace on the right before squaring the ball across the area to Ki, who managed to get a shot away which Gomes held at the second attempt.
The Watford keeper then made a good stop for the cameras as he dived to his left to hold onto Sigurdsson’s ambitious long-range effort, although it was well struck.
As half-time approached and with little of note happening, leading to a feeling this game needed a goal, the breakthrough was to be broken three minutes before the interval – and it is not a moment Mawson will not want to look back on.
The Swansea centre-half was under no real pressure when a lapse in concentration saw him miscontrol the ball, Capoue was alert to the opportunity and although he saw his first effort blocked, he was able to curl in the rebound with the help of the far post to make it 1-0.
The home side were soon to be pouring forward again through Tom Cleverley, he found Deeney on the left side of the box and he slipped in Niang, but his right-footed curler was held by Fabianski.
Niang was to contribute to the first significant moment of the second half, miscontrolling the ball on halfway which enabled Naughton to play a long pass up to Llorente, who found Sigurdsson and the former Tottenham Hotspur midfielder struck a left-footed shot wide of Gomes’ left-hand upright.
With Doucuore giving another assured display at the base of the midfield, breaking up play and seeking to kick-start attacks where possible, the Hornets continued to look in relative control, although their opponents saw a promising situation go begging when Ki overhit a good crossing opportunity from the left.
After Doucuoure had struck a rising shot over from 30 yards, Fabianski had to react smartly at his near post to beat away a stinging Janmaat drive from the right side of the area.
Clement made his first change in the 58th minute as Borja Baston replaced Narsingh, but not before Fabianski had to be watchful as another long-range strike from Doucoure deflected off Deeney, taking it closer to the Swansea keeper’s near post than he would have liked.
Watford’s first substitution came in the 63rd minute as Christian Kabasele replaced Amrabat and with it came a formation change to three at the back, while Niang moved infield to operate more alongside Deeney.
After Carroll had replaced Fulton, the visitors were appealing for a corner when a dangerous Naughton cross was headed behind. But replays showed referee Lee Mason was correct in adjudging Mariappa’s header had come off Llorente before going behind.
If anything though, the formation change had helped Swansea more than their opponents; they were having more of the possession and creating more crossing opportunities.
Mazzarri made his second change in the 78th minute with Niang making way for Okaka and within a minute of coming on he’d thought he’d scored his side’s second of the game, acrobatically volleying a Janmaat cross past Fabianski, only for his celebrations to be curtailed by the assistant’s flag.
The substitute was certainly making an impact though, as moments later he surged forward before sliding a pass sideways to Capoue, who fired over from the edge of the box.
Jordan Ayew came on for Llorente to complete Swansea’s changes, the substitution coming before Gomes had to stretch to punch away a dangerous inswinging free-kick from Sigurdsson on the left.
Medical staff from both sides were required on the pitch when a flailing Doucoure arm caught Borja full in the face as he tried to defend a cross and Janmaat was also injured as he sought to challenge for the same ball, but after receiving treatment both players were able to continue.
Behrami made his return from injury as an 88th-minute replacement for Cleverley and Doucoure tested Fabianski with his latest strike from range, before Sigurdsson headed a good cross from the right wide.
There were alarm bells ringing in the third minute of injury time when the Swans broke forward two-on-two, but as Sigurdsson went round Mariappa to open up the shooting opportunity the back-tracking Doucoure epitimosed his performance by getting in a crucial challenge as the Hornets all but mathematically made sure of a third consecutive season in the top flight.
Watford: Gomes; Janmaat, Prodl, Mariappa, Holebas; Capoue, Doucoure, Cleverley (Behrami 88); Amrabat (Kabasele 63), Deeney, Niang (Okaka 78). Not used: Pantilimon, Success, Mason, Pereira.
Swansea City: Fabianski; Naughton, Fernandez, Mawson, Olsson; Fulton (Carroll 67), Fer, Ki; Narsingh (Borja 58), Llorente (Ayew 81), Sigurdsson. Not used: Nordfeldt, Van der Hoorn, Routledge, Kingsley.
Attendance: 20,272 (1,621 away fans).
Referee: Lee Mason.