Arsenal unrecognisable, Mikel Arteta punished and key talking points from Brighton nightmare

This was less a stumble and more an emergency stop from Arsenal.

They were looking to win eight matches at the start of the season for the first time in 123 years.

Brighton had other ideas, dominant from start to finish in a 3-0 win at the Amex Stadium that sends Arsenal into the international break on the back off a nightmare afternoon.

Arsenal were defensively abysmal and got exactly what they deserved. The Premier League champions had their perfect run ripped to shreds.

Barely a minute after the final whistle and Mikel Arteta was back down the tunnel.

He is usually one to embrace each of his players, and most of the opposition's too. Here, though, he shook hands with the officials, marched over to the away end, and then went back to the dressing room.

Arteta must have been as bemused as he was angry. This was an Arsenal side unrecognisable from the one he has moulded into a defensive behemoth in recent seasons.

Arsenal have had poor matches in attack, lacking in invention, but this was their worst defensive performance in a long, long time. Years, rather than weeks or months. This was the first time in more than three years they lost by a three-goal margin.

It was all so slack. Defenders did not engage as Brighton broke forward, allowing Pascal Gross and Charalampos Kostoulas all the time they needed to line up shots for their goals.

The third Brighton goal also summed things up. Kai Havertz stumbled on the ball, conceded a needless corner, and no Arsenal player thought to mark Andres as he headed in.

The basic principles of this Arsenal team disintegrated. From a side that had conceded one goal in four league matches up to this point, it was hard to fathom.

This was a bruising first 45 minutes for Arsenal, who were monstered by Brighton in every aspect.

The Seagulls' pressing was relentless and Arsenal could not live with it.  When Arsenal tried to play out from the back, they were all over the play. David Raya played it straight out early on. Ezri Konsa nearly got caught in his own six-yard box.

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That forced them to go long at times, but the ball did not stick and Brighton did not allow them to get out.

Arsenal were alarmingly open in midfield, with Bruno Guimaraes in particular well off the pace. It was all so sloppy and the exact opposite of what this side normally produces.

This was by far the most uncomfortable they have looked this season. It was incredible, then, that Arteta did not make any half-time changes.

The calmness of Myles Lewis-Skelly, for example, in possession would have been very welcome.

Instead, it was more of the same. Brighton ran through Arsenal, who just could not settle. That much was abundantly clear in the first half and in the first ten minutes of the second.

Still Arteta did not act. By the time he eventually did on the hour mark, Andres had made it 3-0 and put the match to bed. That was a major mistake.

An interesting added dynamic to this result is that it comes right before the international break.

The change in the football calendar means that this one is three weeks long and it will be fascinating to see how Arsenal respond.

Arteta will have almost none of his first-team players with him at the training ground, as they fly off around the world.

The Arsenal boss would have loved for his side to have an immediate opportunity to respond to a performance this bad.

You would back them to, as well, considering how rare it is that the Gunners show up in this manner.

However, three weeks is a long time to reflect on this performance. The first match back is a 12:30pm kick-off on a Saturday, a notoriously tricky time slot after the international break, at home to Leeds.

It is essential that Arsenal respond emphatically when their opportunity to do so eventually comes.