Watford were unable to win at the Emirates Stadium for a third season in a row as they fell to a 3-0 defeat against Arsenal.

While the margin of victory was ultimately comfortable, it could have been anything but had the Hornets made the most of their big opportunity to get on the scoresheet when they were two goals down after the break.

Minutes after conceding the second goal, Watford were awarded a penalty when Roberto Pereyra was tripped in the area but Troy Deeney couldn’t the opportunity to increase the nerves among the home faithful – even though they were leading – as Petr Cech saved his spot-kick.

The Gunners may have still gone on to claim the three points, but the reaction of the home faithful, in particular, would have been fascinating had the visitors got back into the contest.

Watford didn’t need to give their opponents early encouragement but that was exactly what happened in the eighth minute when Skhodran Mustafi headed in a Mesut Ozil free-kick.

Orestis Karnezis had already made one good save from Pierre-Emerick Aubameyang – he was to make an even better one to deny Ozil later in the first half – but the Hornets more than had their share of play and with more conviction and quality in the final third they might have been level at the break.

Richarlison came closest with a free-kick which struck the base of the post; Roberto Pereyra getting the rebound all wrong, while the Brazilian also forced Petr Cech into a good save with a header in stoppage time.

The Hornets started the second half well but all that promise was to be undone when some poor defending allowed Henrikh Mkhitaryan to set up Aubameyang for the second goal.

Deeney then spurned his opportunity to get the Hornets back into the contest from 12 yards and with the Hornets have to chase the game, the Gunners, perhaps predictably, made it 3-0 through Henrikh Mkhitaryan.

Javi Gracia made just the one change as Watford went in search of a third consecutive win, with Kiko Femenia returning to the starting line-up in place of Andre Carrillo.

Heurelho Gomes was not involved in the match-day 18 for personal reasons, with Daniel Bachmann taking his place on the bench.

Having stopped the rot with a 2-0 win at AC Milan in the Europa League and with one eye on Thursday’s return leg, Arsene Wenger made six changes to his starting XI.

Cech returned in goal, Ainsley Maitland-Niles and Rob Holding came into the back four, Mohamed Elneny was in a holding midfield role, while Alex Iwobi and Aubameyang formed half of the Gunners’ front four.

David Ospina, Calum Chambers, Jack Wilshere and Danny Welbeck dropped to the bench, while Laurent Koscielny and Aaron Ramsey were given the afternoon off.

The first interesting development of the afternoon was that Watford lined up in a 4-4-2 formation – and not 4-2-3-1 as expected – with Richarlison pushing up alongside Troy Deeney.

It was the home side who sought to make the early running, creating their first chance in the third minute when Elneny passed the ball to Granit Xhaka, who put Aubameyang away behind Sebastian Prodl, but Orestis Karnezis making a good blocking save with his legs.

The Hornets were soon on the front foot though, with Pereyra coming in off the left to slide in Richarlison, who hit a rising angled drive wide of Cech’s near post.

But it was Arsenal who were to make the breakthrough in the eighth minute when, having won a free-kick on the left, Ozil floated his delivery into the middle and Mustafi got up well to head back across Karnezis and into the far corner to score his club’s 1,000th Premier League goal.

The visitors’ response to the setback was positive; firstly winning two corners before Pereyra played a fine long pass over the top to try and put Richarlison in, but the Brazilian held the ball up before laying it back to Abdoulaye Doucuoure, whose first-time effort forced Cech to parry.

Arsenal had the next opportunity in the 17th minute when Elneny slid in Sead Kolasinac on the left but his slide-rule pass across the six-yard area was just too far ahead of the stretching Aubameyang at the far post.

Iwobi then curled an angled shot over after Elneny, who was having quite a lot of influence on proceedings, had played in the overlapping Maitlind-Niles to cross from the right.

But Watford were to come very close to levelling in the 26th minute when, after Xhaka had fouled Femenia right of centre around 25 yards out, Richarlison got his free-kick up and over the wall and it struck the base of Cech’s near post and the rebound fell to Pereyra on the right side of the six-yard box, but he blasted over.

Arsenal’s response to that let off was to almost double their lead; Ozil latching on to a pass and dancing through a challenge to do everything right, but beat the outstretched left leg of Karnezis, who make a superb save.

It was then Adrian Mariappa’s turn to make a fine challenge to prevent Aubameyang pulling the trigger after the ball had broken for the former Borussia Dortmund man following a Prodl intervention.

Watford came on strong as the half drew to a close though, with Holding forced to scramble a Femenia pull-back over his own bar after Watford had worked a short corner routine from the left which enabled the Spaniard to get in around the back of the Gunners’ defence.

The Hornets were to have an even better opportunity in injury time when Femenia did well on the right and played in a good cross which the stooping Richarlison headed towards the near post, but Cech did well to push it behind.

The Gunners had the first chance of the second half when Xhaka chanced his arm from 25 yards and Karnezis caught the well-struck effort at the second attempt.

Watford were soon back on the front foot, with Femenia hitting a well-struck half-volley that was blocked behind by Holding. Jose Holebas’ resultant corner was to cause the Gunners all types of problems, with Deeney’s flick taking the ball beyond Cech but possibly just out of reach of Mariappa’s head as well.

Holding was the first player to be booked in the 55th minute when he crudely prevented Richarlison from leading a counter-attack, but the majority of the game continued to be played in the Arsenal half.

But the game was to take an even bigger swing in the Gunners’ favour three minutes later with a second goal that was poor from the visitors’ perspective.

A Mariappa clearing header fell for Mhhitaryan who ran at a retreating Hornets rearguard and with Prodl trying to play offside, he slipped the ball through to Aubameyang, who rounded Karnezis to make it 2-0.

Gracia immediately made his first change, bringing on Will Hughes for Femenia, but within a couple of minutes of going two behind Watford were handed a great chance to halve the deficit.

Martin Atkinson had no hesitation in pointing to the spot when Maitland-Niles tripped Pereyra in the area, but Deeney opted to go to Cech’s right, the keeper guessed correctly and saved, prompting the biggest cheer in the Emirates of the day.

Welbeck came on for Iwobi and Stefano Okaka replaced Pereyra, but Watford were fortunate not to concede a penalty of their own when Mariappa cleaned out Mkhitaryan inside the area.

Injury was to end Mustafi’s game in the 72nd minutes as Chambers took his place and Mkhitaryan was also to go off five minutes later and be replaced by Wilshere, but not before he had made it 3-0.

Ozil was allowed to get into the space on the left, his low cut back broke for Aubameyang and the striker laid the ball off to Mkhitaryan to beat Karnezis with a shot which rather went through the Hornets keeper.

Gracia completed his substitutions by replacing Janmaat with Miguel Britos as the visitors’ kept plugging away; Okaka stabbing the ball goalwards for Cech to save after Mariappa had ventured forward to cross.

It took another good stop from Karnezis to prevent the hosts from scoring a fourth with four minutes remaining when he did well to parry a stinging Welbeck drive behind after being set up by Wilshere.

Xhaka was to be booked late on for pulling back Hughes, leading to a free-kick in a promising position but again Watford couldn’t make the most of it as Prodl skied a half-volley over the bar, allowing Cech to become the first Premier League goalkeeper to keep 200 clean sheets.

Arsenal: Cech; Maitland-Niles, Holding, Mustafi (Chambers 72), Kolasinac; Elneny, Xhaka; Iwobi (Welbeck 66), Ozil, Mkhitaryan; Aubameyang. Subs not used: Ospina, Wilshere, Nelson, Nketiah, Willock.

Watford: Karnezis; Janmaat (Britos 77), Prodl, Mariappa, Holebas; Femenia (Hughes 61), Capoue, Doucoure, Pereyra (Okaka 66); Deeney, Richarlison. Subs not used: Bachmann, Sinclair, Gray, Carrillo.

Bookings: Holding for a foul on Richarlison (55); Holebas for a foul on Mkhitaryan (66); Xhaka for a foul on Hughes (89).

Attendance: 59,131.

Referee: Martin Atkinson.