It is not that often Watford will score three goals and it can be justifiably argued they didn’t deserve at least a point, but that was the case this afternoon as the Hornets were beaten 4-3 by Southampton at Vicarage Road.

The early signs were promising for Walter Mazzarri’s side, who lined up in more of a 4-4-2 formation, as Troy Deeney fired them into a fourth-minute lead. But after starting slowly, the Saints grew into the game and by the time Dusan Tadic had equalised they had control of midfield as their opponents’ defensive vulnerabilities were capitalised on for the first time.

Watford were to be opened up again in first-half injury-time as Nathan Redmond fired the visitors into the lead at the break and, worryingly, there was to be no change of approach from the Hornets for the first half of the second period as Southampton continued to control proceedings.

Having offered very little in attack after the interval, the introduction of Isaac Success did see Watford begin to threaten and it was the substitute who set up the equaliser for Stefano Okaka.

The hosts weren’t level for long though, as Manolo Gabbiadini pounced on a mistake from Heurelho Gomes and that was quickly followed by Redmond’s second of the game before Abdoulaye Doucoure netted Watford’s third in stoppage time. By that stage though, many Hornets fans had voted with their feet and left the game early.

Mazzarri made two injury-enforced changes from the side that drew 1-1 West Ham United seven days previously.

Daryl Janmaat joined Mauro Zarate in being ruled out so Sebastian Prodl returned at centre-half, with Younes Kaboul switching to right-back, and Okaka started up front.

The Saints were unchanged from the starting XI that ran Manchester United close in last Sunday’s EFL Cup final.

Watford’s skipper came into the game needing just one goal to move level with Cliff Holton in fourth place on the club’s all-time scorers’ list and it took him just four minutes to achieve his latest scoring landmark.

The goal originated from a Kaboul long throw from the right, Okaka did very well to hold hit up and Deeney guided a fine, controlled left-footed half-volley beyond Fraser Forster to net his 100th goal in league competitions for the club and 105th in total.

It took the visitors a few minutes to regroup after conceding and their first clear opening didn’t come until the 12th minute when James Ward-Prowse was played into space on the right side of the 18-yard box and his stinging shot was turned behind into the side netting by Gomes.

Cedric received the game’s first yellow card soon after for pulling back Valon Behrami and then shots were exchanged at either end; first Gomes was equal to a Gabbiadini side-footed effort, M’Baye Niang fired wide from distance and then Cedric also fired the wrong side of the upright from his perspective.

Watford had the next opportunity in the 23rd minute when Okaka headed a Jose Holebas inswinging corner from the right over and soon after Etienne Capoue fired a shot from the edge of the area wide of Forster’s near post after the home side had a promising counter-attack.

But Southampton were to pull level in the 28th minute when Tadic’s attempt to play in Redmond was played back to him by a poor clearance from Miguel Britos, who had Kaboul partially in his way, and Tadic calmly steered it into the far corner to make it 1-1.

Gomes did appeal for offside against Redmond, who was in an offside position when the ball was struck and did jump over Tadic’s effort but the officials decided he was not interfering with play.

Gabbiadini was booked in the 33rd minute for a high boot that caught Behrami in the face but the momentum swung in the Saints’ favour following the goal as their opponents lost some of their composure and were not looking that convincing defensively. The best they were able to muster though, was a long-range effort from Cedric that didn’t overly trouble Gomes.

Okaka had reason to feel aggrieved in the last minute of normal time when he was booked for overly protesting by Jon Moss, having complained because his shirt was clearly being held by Stephens.

The Hornets had been second best since conceding and that fact was to be reflected by the interval scoreline as Southampton took the lead in the second minute of injury time.

Redmond started the business end of the move by seizing on a loose pass and dancing around Behrami with ease as he accelerated forward and found Ward-Prowse. He fed Tadic to his right and outside him and the scorer of the visitors’ first goal laid the ball back to Redmond, who swept a shot home in-off the far post to make it 2-1.

Watford would have been looking to make a quick start to the second half, but they continued to look susceptible defensively and remained second best in midfield.

Southampton had the first chance of the second period when Gabbiadini accelerated away from Britos on the left and cut into the area, but instead of taking the chance himself he tried to lay the ball off to a teammate and Behrami was able to scramble the danger away.

The Hornets were almost opened up again on the hour when, after their attacking throw-in had been cleared, Southampton broke three-on-two but they were unable to capitalise on the situation as the ball was put behind for a corner.

Following that delivery from the left though, the ball was only cleared as far as Tadic on the edge of the area and he chested it down before hitting a right-footed half-volley which Gomes had to tip over.

The Hornets goalkeeper came to his side’s rescue again soon after when he got down low to his right to make a smart stop after the outstretched leg of Maya Yoshida had turned a free-kick goalwards.

The home side had created little of note attacking-wise since the break but they did have a chance when Okaka battled for the ball and it dropped invitingly on the volley for Niang in space on the right side of the area, but he got his attempt all wrong and skied the chance over.

Mazzarri finally decided to make a change in the 70th minute as Success replaced Capoue but within a minute of coming on the substitute needed treatment after being caught in the face by Cedric.

But the arrival of Success lifted his side’s attacking play and in the 73rd minute Forster was forced to make his first save of the second half, blocking an angled Okaka shot with his legs after he had been slipped in on the right side of the 18-yard box by Tom Cleverley.

Another Hornets chance came and went when a deep Holebas delivery dropped for Deeney at the far post but he dragged his shot wide of Forster’s right-hand upright.

Ward-Prowse was replaced by Sofiane Boufal in the 78th minute but within 60 seconds the Hornets were level.

A Niang cross-field ball from the right was latched onto by Success. He ventured forward before laying the ball off to Okaka, who returned a pass to the substitute on the left and he played a low cross into the near post where Okaka arrived on the edge of the six-yard box to find the back of the net via the inside of the near post.

But the Hornets were to be level for less than five minutes due to an incident Gomes will want to quickly forget.

A Boufal curling shot from 25 yards did bounce up awkwardly in front of the keeper but he would have still expected to do better, but the ball squirmed from his grasp and Gabbiadini was lurking to pouch his sixth goal in his first four games for the club to make it 3-2.

That was to be the Italian’s last involvement as he was immediately replaced by Shane Long, but a bad afternoon for the home side was to get rapidly worse as the ball was played out to Redmond on the left and he teased Prodl before firing a right-footed shot high to Gomes’ right to put the visitors 4-2 up.

Boufal could have made it five in injury time when he twisted and turned on the left side of the penalty area before striking a rising drive wide of the near post and into the side netting.

But the last goal of a mad ending to the game was to be scored by Watford as a Niang cross from the right was flicked on by Britos and Doucoure scored from close range minutes after coming on the pitch as a late replacement for Okaka.

Watford: Gomes; Kaboul, Prodl, Britos, Holebas; Niang, Cleverley, Behrami, Capoue (Success 70); Okaka (Doucoue 89), Deeney. Not used: Arlauskis, Mariappa, Cathcart, Zuniga, Stewart.

Southampton: Forster; Cedric, Stephens, Yoshida, Bertrand; Davis, Romeu; Ward-Prowse (Boufal 78), Tadic (Clasie 87), Redmond; Gabbiadini (Long 84). Not used: Hassen, Rodriguez, Cacares, McQueen.

Bookings: Cedric for a foul on Behrami (14); Gabbiadini for a foul on Behrami (33); Okaka for dissent (44); Prodl for a foul on Tadic (73).

Attendance: 20,617.

Referee: Jon Moss.