Arsenal had to come from behind to claim a 3-1 victory against West Ham United on Saturday afternoon.

Marko Arnautovic gave the Hammers a first-half lead but Unai Emery's men replied quickly through Nacho Monreal who levelled the score. An unfortunate own goal from debutant Issa Diop and a stoppage time goal from Danny Welbeck helped Arsenal to victory to earn their first three points of the season and the first under Emery.

Vital importance of the modern day full-back

The role of the full-back has changed vastly over the last decade with the demands of the game leading to the full back being required to attack almost as much as they defend.

This was visibly apparent on Saturday, as Nacho Monreal found himself in a poacher’s position as he equalised from six yards out smashing the ball in to a half empty net after taking a touch to compose himself.

Monreal has become an unlikely source of goals for Arsenal in the last couple of seasons, as the Spaniard scored an impressive five Premier League goals last season and has already claimed his first of the season in just his second appearance.

Hector Bellerin also played a big part in Arsenal’s 3-1 victory, constantly providing an outlet for the Gunners on the right wing in attack. Although, his attacking tendencies often leave him out of position and liable to defensive mistakes, Bellerin showed good quality on Saturday and was a constant headache for the West Ham defence.

Bellerin’s blistering pace is a great asset for Arsenal and proved to be the difference between the two sides as the Spaniard claimed two more assists, finding Monreal for the equaliser before picking out Welbeck with a low cross to seal the three points.

Embed from Getty Images

Defensive issues still apparent

It was a game full of chances for either side and while it was thoroughly entertaining to watch an open, attacking game of football, Arsenal fans will be hoping that Emery can reaffirm the defence and limit opposition chances.

In conjunction with the attacking threat that the full-backs provide, it can often leave Arsenal susceptible to conceding goals and had the Gunners been playing a more clinical side, Saturday’s result could have been very different.

West Ham will be ruing the chances they wasted at the Emirates as Arnautovic, Michail Antonio, Robert Snodgrass and former Arsenal man Lucas Perez all missed guilt edged chances.

The Gunners defence has proved to be their downfall for the last few seasons, particularly away from home last season. Whilst summer signing Sokratis Papastathopoulos will be hoping to provide more stability, Arsenal are yet to keep a clean sheet in their three games this season.

Next week's opponents Cardiff City have yet to score a league goal in their three games and may deliver Arsenal the chance to keep a clean sheet on the road which could give them some much needed confidence, something which was rarely seen in Arsene Wenger’s last season at the club.

Embed from Getty Images

Game changing substitutions

Unai Emery hasn’t been afraid to make early substitutions and has made half time switches in Arsenal’s last two matches. Emery withdrew Alex Iwobi at half-time for Alexandre Lacazette.

Lacazette has yet to make a start under the new boss but must be close to pushing for a starting spot. The Frenchman had an influence on Saturday, changing the pace of the game and giving Arsenal more intensity and speed in their attacking play as Pierre-Emerick Aubameyang was shifted out wide while Lacazette occupied the central striking role in the second half.

Arsenal received a slice of good fortune with their second goal of the afternoon which came after Lacazette controlled the ball on his chest and swivelled before his drive across the box deflected off Diop and hit the back of the net.

Matteo Guendouzi impressed again with his persistence in midfield but was replaced by Lucas Torreira after 55 minutes who gave Arsenal a different dimension in midfield and helped to control the game efficiently as the Gunners persisted in an end-to-end match.

Danny Welbeck replaced Aubameyang as the final Arsenal change of the afternoon and marked his first appearance of the season with a goal. The Englishman found space in the box and was allowed time to control, turn and finish past Fabianski in the West Ham goal.