Watford suffered a difficult early afternoon beneath the North London spring sunshine as Tottenham Hotspur capitalised on the chance to move within four points of leaders Chelsea with an emphatic 4-0 victory.

The Hornets started positively before their opponents increasingly began to boss territory and possession. But with just over half-an-hour gone and the game still goalless few inside White Hart Lane would have predicted Spurs would be 3-0 in front by the break.

But after Dele Alli made the breakthrough with a magnificent 25-yard curler from outside the left edge of the penalty area in the 33rd minute, the hosts – aided by the Hornets not closing down as well as they should have done – set about ensuring they were to move within four points of leaders Chelsea.

Eric Dier doubled his side’s lead in the 39th minute when he fired home after a Son Heung-min cross had deflected out to him off Abdoulaye Doucoure. And two goals in six minutes became three in 11 when Son was afforded the time and space to fire past Heurelho Gomes.

It looked like being a very long second half for the Hornets when Son volleyed in his second ten minutes after the break. But the hosts were then largely content to sit on their lead – although Son should have completed a hat-trick late on – while Watford kept plugging away without really threatening to endanger Hugo Lloris’ clean sheet.

Although Watford’s injury-enforced absences weren’t as bad as Walter Mazzarri’s pre-match comments on Saturday had suggested they might be, the Hornets boss made four changes from the team that beat West Bromwich Albion 2-0 but also decided to field an attack-minded line-up for a game that many would have regarded as a free hit.

With Miguel Britos suspended and Sebastian Prodl injured, the Watford head coach also decided to rest Troy Deeney and Etienne Capoue to the bench.

Their places were taken by Adrian Mariappa, who made his first Premier League start since returning to Vicarage Road and 250th appearance for the club in total, Daryl Janmaat, Stefano Okaka and Isaac Success, who came in for just his second start of the campaign.

The Hornets’ defensive problems were mitigated to an extent by having Christian Kabasele available again from a list of substitutes which also included youngsters Brandon Mason and Andrew Eleftheriou.

Spurs came into the game seeking a seventh straight win in all competitions and Mauricio Pochettino made three changes to the team that produced a dramatic comeback to win 3-1 at Swansea City on Wednesday.

Lloris had from recovered the illness that came him out of the success in Wales and replaced Michel Vorm, who picked up an injury in that game, Kieran Trippier was preferred to Kyle Walker at right-back and Moussa Sissoko made way for Vincent Jansssen.

Although he was back from injury quicker than expected, the Spurs boss unsurprisingly decided there was no need to rush Harry Kane back into the starting XI and the England striker was among the replacements. They were meant to include Victor Wanyama, but he was injured in the warm-up and his place was taken by Josh Onomah.

The Hornets were billed as a bold 3-4-3 formation pre-match but they started with two banks of four which were soon put under pressure by the hosts winning their first corner from which Jan Vertonghen was to see a shot blocked.

The visitors soon had an opportunity to have an early strike at goal though, when Jose Holebas was fouled 30 yards out. The retired Greek international took the free-kick himself and although he got it up and over the wall, Lloris wasn’t particularly troubled.

Gomes had to go to ground low to his right to deal with a shot from Son soon after and then the South Korean saw a cross from the left deflected onto the outside of the near post by Janmaat.

An entertaining opening had already taken on something of an end-to-end approach and it took a good blocking save from Gomes to prevent Spurs from taking the lead in the ninth minute when his legs kept out a close range effort from Janssen, who turned Craig Cathart in the area after being slipped in by Christian Eriksen.

The visitors were playing their part though, and Cathcart hit a bouncing ball into the side netting after Holebas had whipped in a free-kick from the left before M’Baye Niang warmed Lloris’ gloves with a curling effort from outside the 18-yard box.

Watford were more than holding their own but they escaped twice in quick succession approaching the 20-minute mark, being particularly fortunate to do so on the first occasion when a ball towards the right side of the area was volleyed back across the six-yard box by Trippier. Although it deflected off Cathcart, Janssen didn’t anticipate at the back post and the ball struck him and ballooned up and off the face of the crossbar before Watford scrambled it clear.

The same type of move was almost repeated inside a minute, but this time Trippier’s first-time delivery was too far ahead of the Spurs striker and another chance to make the breakthrough went begging for the hosts.

Tottenham were increasingly turning the screw and the next five minutes was played almost exclusively in their opponents’ half of the pitch, but Watford withstood that pressure. But in the 33rd minute they were undone by a moment of brilliance.

The hosts did well to extricate themselves from a tight situation in the right-back area as Watford pressed, Mousa Dembele surged forward through midfielder and although he was hauled down by Doucoure, referee Anthony Taylor played advantage. The ball was then worked up to Alli, who laid it off on the right side of the penalty area, and received it back before curling a magnificent right-footed shot over Gomes and into the top corner from all 25 yards to make it 1-0.

Doucoure was subsequently booked for the foul, but having made the breakthrough it only took Spurs another six minutes to double their lead.

The goal again originated from the left as Son played in a cross that struck Doucoure and broke for Dier, who didn’t have to break stride as he hit a right-footed shot into the ground and past Gomes from the edge of the 18-yard box.

The Hornets would have been hoping it would have got no worse before the interval but in the last minute of normal time in the first half Tottenham netted a third.

This time Eriksen was the creator, rolling a pass into Son, who had the space to come infield and was not closed down as he swept a left-footed shot beyond Gomes to make it 3-0 at the break.

Janssen had the first opening of the second period, heading Trippier’s delivery from deep wide, and then it took a covering challenge from Janmaat to prevent Vertonghen from having a clear opening in the area after the centre-half had been picked out by Eriksen as the home side sprung the counter from a Watford corner.

The Hornets were trying to be positive and Janmaat hit a shot wide, only for Spurs to score a fourth in the 55th minute.

Again there was little pressure on Eriksen as he was allowed to venture forward before feeding the overlapping Trippier, who struck a first time cross to the back post where Son met it first time on the volley and beat Gomes at his near post to score his second after the afternoon.

Mazzarri’s response was to bring on Camillo Zuniga for Doucoure; Pochettino also made his first change moments later and it demonstrated little sympathy for the Hornets as Kane made his return from injury in place of Janssen.

Watford kept plugging away and they did create an opening in the 66th minute when a back-heeled flick from Okaka gave Success the chance to run in behind, but he dragged his shot across the face of goal and wide after being shut down by the recovering Dembele.

Deeney replaced Nordin Amrabat, who had struggled to affect the game, with 20 minutes remaining, but beforehand the referee needed to get involved when Alli and Holebas got involved in a spat following a challenge.

And it was Deeney who missed a good chance to reduce the deficit when he had the time to bring down a Holebas cross from the left, but he tried to find the top corner with the outside of his right foot and curled the shot wide.

After Sissoko replaced Dembele, Kane went close to marking his return with a goal, but he was unable to get his head on the end of Trippier’s latest good delivery into the near post.

However, Son really should have been celebrating a hat-trick with ten minutes left when he was set up by Kane and only had Gomes to beat, but he put his right-footed finish the wrong side of the Hornets keeper’s left-hand post.

The South Korean went closer again in the 84th minute, striking a right-footed half-volley on the turn off the top of the crossbar after Dier had lifted the ball into him.

Kabasele then made his return to action as a late replacement for Okaka before the substitutions were completed by Onomah coming on for Son.

Kane then almost made it five with the last attempt of the game, cracking a 25-yard free-kick off the top of the bar after the striker had been fouled by Cathcart, but a convincing home victory had long since been wrapped up by the hosts.

Tottenham Hotspur: Lloris; Trippier, Alderweireld, Vertonghen, Davies; Dier, Dembele (Sissoko 74); Son (Onomah 88), Eriksen, Alli; Janssen (Kane 60). Not used: Lopez, Walker, Nkoudou, Wimmer.

Watford: Gomes; Janmaat, Mariappa, Cathcart, Holebas; Amrabat (Deeney 70), Cleverley, Doucoure (Zuniga 59), Niang, Success, Okaka (Kabasele 84). Not used: Pantilimon, Capoue, Mason, Eleftheriou.

Bookings: Doucoure for a foul on Dembele (34).

Referee: Anthony Taylor.