After managing to come back from a two-goal first-half deficit at Stamford Bridge, Arsenal were felled in their first away league game of the season by a late Marcos Alonso winner.

In a game that had a scarcely believable opening 45 minutes, the Gunners were perhaps unlucky to not come away with at least a share of the spoils. Defensive errors and a lack of capitalization on great chances ultimately haunted Unai Emery’s side.

The team selection as unexpected in many ways. While Petr Cech had already been confirmed to retain his place at number 1 against his old club, there were some changes in the middle.

Aaron Ramsey was ineffective against Manchester City last week, so he made way for Alex Iwobi, who took up a place on the wing with Mesut Ozil moving into the central attacking midfield position.

It is a credit to 19-year-old Matteo Guendouzi’s performance in the season opener that he held onto his starting position alongside Granit Xhaka in midfield, with fellow new signing Lucas Torreira starting on the bench.

Nacho Monreal took over at left-back in place of the injured Ainsley Maitland-Niles, despite fears over a knee injury. The rest of the team remained the same, with Pierre-Emerick Aubameyang occupying the sole striking position.

Both clubs competing in Stamford Bridge had come off second best to the reigning champions since the season’s start – Chelsea in the community shield and arsenal in the season opener – so this game was set up to give a better indication of where both clubs were at under their new managers.

While Eden Hazard, who was determined to be lacking match fitness, only made a place on the bench to start, Chelsea burst out of the gates.

The first half of this match was probably the most entertaining half of Premier League football thus far this season across all of the matches, but it certainly didn’t seem like that was going to be the case after the first 20 minutes.

With 9 minutes on the clock, with the Arsenal defence seemingly nowhere to be find, Pedro had his name on the scoresheet for the second game in a row.

New Chelsea signing Jorginho played the ball from deep within his own half down the wing to Marcos Alonso, who had plenty of time to play a ball in due to Hector Bellerin being found out of position. His ball found Pedro, who calmly slotted the ball by Cech, who stood no chance, to make it 1-0 to the home team.

10 minutes later, Aubameyang had a golden opportunity to open the scoring of the Emery era. Guendouzi played a sublime ball to Bellerin in a forward position, who found Aubameyang with pass just as he reached the byline.

The Gabonese forward didn’t have much to do, with Chelsea stopper Kepa Arrizabalaga in an awkward position, but he scooped his effort from close-range over the bar. Disappointing, but it proved immediately more costly, when Chelsea broke forward from the ensuing goal kick.

Last season, Alvaro Morata had a torrid time for Chelsea up-front. Brought in for big money, the Spanish forward was not producing the results expected of him. In league and cup appearances against Arsenal last season, the striker was found wanting – but not today.

Cesar Azpilicueta started the move from the back, launching down the right side. One simple pass to Morata, and somehow it’s him against Arsenal’s final defender, Shkrodan Mustafi.

With a turn-inside, Mustafi is left for dead and Morata finishes to the bottom right with Cech rooted to the spot. For the second time in the opening 20 minutes, the Arsenal defence was left-for-dead and the side were two-nil down.

All emery needed was something to go right for his side – like the earlier Aubameyang effort – but with just over half an hour on the clock, it didn’t seem like it was going to come. Henrikh Mkhitaryan found himself in a position very similar to Aubameyang, and once more, it was a miss.

Heads could have dropped with this being the case, but credit to Emery and his side, that wasn’t to be the case.

Arsenal had gradually been growing into the game after a poor start, and this final started paying dividends in the 37th minute. Monreal did excellently to gain some space on Willian not far from the Chelsea goals, and then found Alex Iwobi.

Iwobi pulled a pass back for Mkhitaryan, who this time made absolutely no mistake to score Arsenal’s first goal of the season and the first goal put past Arrizabalaga as well.

Just a few minutes later the roles were switched, with Mkhitaryan becoming provider for Iwobi.

The Nigerian international found himself on the penalty spot, almost the exact position he had seen his teammates miss two chances from already, but made no mistake, and put the ball high into the net to make it two-a-piece.

There was still more drama to come in an exciting first half. Arsenal looked a different side from the beginning of the match, and almost had the chance, somehow, of going in ahead at half time.

Iwobi, who had found the net just minutes earlier, found himself with a gilt-edge opportunity in a very similar position. Again, it was Mkhitaryan who fed the ball to him, but this time, just before the half-way mark, Iwobi skied over the bar.

A crazy half of football, 2-2.

Torreira was introduced for the second half in the stead of Xhaka, meaning the two new midfielders would be manning the centre of the field.

Not long into the second half, in an effort to mix things up, Chelsea manager Maurizio Sarri introduced the considerable talents of Hazard and new signing Matteo Kovavic to the field.

Ramsey and Alexandre Lacazette were introduced for the away side, and the latter must take a lot of the fault for what would end up being the winning goal.

Lacazette played a poor backwards pass that was capitalized by the Blues, with Hazard dribbling down the left side, making it to the byline, and then cutting a low pass towards the near-post. Alonso found himself in an inviting position, and side-footed the ball past Cech to make it 3-2.

A goal down, Arsenal threw the kitchen sink at the Chelsea defense for the remainder of the match, but failed to fashion a clear-cut goal scoring chance. The game came to a close at 3-2, and Sarri’s side finished deserved winners in what was a crazy match-up.

Arsenal created a lot of chances in the match, but failed to convert them to goals on many occasions. The defense was erratic, and were consistently found out of position and exposed, especially for the opening two goals. Even with that being the case, if some of the chances were converted, Arsenal could have came out as winner in this match, so on-the-day, they were unlucky.

It's too early in Emery’s time as manager to draw any major conclusions, but after two games, Arsenal are on 0 points. Next up is West Ham United, who have also lost both of their opening games – it’s a must-win.