Crystal Palace were taken apart by a rampant Arsenal who scored four goals inside 25 minutes and condemned them to a heavy 4-1 defeat.

Defenders Nacho Monreal and Laurent Koscielny, as well as winger Alex Iwobi, found the back of the net inside 15 minutes before Alexandre Lacazette made it four inside a quarter of the first half.

Palace began the restart as though it was goalless and ruined a potential Gunners clean sheet when Luka Milivojevic chested and volleyed into the bottom corners 12 minutes from time.

However, Yohan Cabaye’s injury shortly before full-time compounded a miserable afternoon for the Eagles.

Here are five things we learned…

1. The best and worst 25-minute starts by two Premier League clubs this season

This injury-ravaged Crystal Palace side had enough about it to warrant Arsenal being cautious of being too forceful in their attacks, but no one expected them to concede three goals inside 15 minutes.

When Monreal’s header went in, it was a poor start, then Iwobi’s was very poor, and then Koscielny’s was terrible.

So when Lacazette found the back of the net 23 minutes in – with still an entire hour to play – it was by all accounts indefensible.

2. Palace looked defeated before they even began

When Arsenal found space down the left side before Iwobi’s strike inside the area was tipped over the bar for a corner, it only took seconds for Monreal to break free of James McArthur for the opener.

However, the defending leading up to – and during – the corner was too passive and almost lethargic.

Cue the second four minutes later, and Milivojevic had only just got to Iwobi after Monreal had acres of space to dribble into the box.

Errors you would expect to have been ironed out in match preparation were evident very quickly.

3. Dann and Sakho’s absences were fully exposed in this game

He is not the fastest or the strongest, but Scott Dann as a presence in the back four as a leader usually sharpens Palace’s defence.

Conversely, the athleticism of Mamadou Sakho enables the Eagles rearguard to combat against the opposition’s best attacking threats – on this occasion, Lacazette.

Now that Dann is expected to miss the rest of the season and Sakho still a month or two away, Martin Kelly and James Tomkins – who usually feature alongside the aforementioned defenders – had a very real test in what is ahead of them.

4. Two players return, one goes out

Both Joel Ward and Andros Townsend returned to the bench following injury layoffs in recent weeks, while the club is still without others for the time being.

But like Palace’s luck, or lack thereof, it was yet again time for someone to go down in writhing pain.

Yohan Cabaye exited the game shortly before full-time on a stretcher before being seen with his ankle in a boot.

It’s too early to know how long he will be out for but initial fears do not fill fans with hope.

5. But in context, this is one of the few times Palace has lost in recent games

Heading into the game Palace had only lost one of their last six Premier League matches, which was the reverse in a 3-2 defeat to Arsenal at Selhurst Park.

Moreover, they were undefeated in 11 of their previous 12 games.

With that in mind it becomes more comforting to believe this is not the be-all-end-all.

There are certainly some negatives to name a few, however the overall picture could be a lot, lot worse.