Arsenal crashed to an embarrassing defeat at West Brom on Saturday afternoon as they gifted Tony Pulis only his second home win of the season.

If there was ever any illusion that Joel Campbell might have a long-term future at Arsenal, this was shattered when Arsene Wenger opted to play Kieran Gibbs ahead of him against the Baggies. With Hector Bellerin returning to the side and both Laurent Koscielny and Olivier Giroud passed mentally fit to feature, Arsenal went into the game with their strongest possible lineup given the personnel available.

It was a lively start to the game from the Gunners who knew that a win would take them clear at the top of the table, albeit possibly only for a few hours, and they looked like a well-focused side, something that isn’t always the case after an international break nor against sides of the calibre of anyone managed by Tony Pulis. Well, focused initially at least.

The signs were there early on that it could be a bad afternoon. There were just 10 minutes on the clock when Arsenal picked up yet another injury. Francis Coquelin went down with what seemed to be a knee problem and was replaced by Mikel Arteta.

Who doesn’t love November?

A cagey first half saw Arsenal dominate yet struggle to create any clear chances until that man, Mesut Ozil, stepped up with yet another assist. Delivering a delightful freekick into the West Brom box after 27 minutes, he found Olivier Giroud completely unmarked and the Frenchman made no mistake from a few yards out.

Of course, Arsenal being Arsenal they then managed to concede from a freekick of their own just seven minutes later despite West Brom not even being close to being in the game at any point. Was it a freekick in the first place? Probably not, but that’s no excuse for defending like a bunch of monkeys on Valium.

But Arsenal weren’t done yet.

A Mikel Arteta own goal then gave the Baggies the lead just five minutes short of the break and, somehow, Arsenal were losing a game yet again to a side who had mustered fewer shots on target than goals scored.

The Gunners had conceded as many to West Brom as they had in their last five league games.

Comedic.

There was no reason to panic at this point, however. Of their last 26 games in which Arsenal had taken the lead, they’d won 25 of them and West Brom had offered so little in the game that a more focused Gunners side in the second period would surely be more than enough to collect the points.

Just two minutes of the second half had passed when Mesut hit the post but that was overshadowed by the second injury of the game; Arteta’s calf giving him yet more trouble and the sub had to be subbed. Maybe it wasn’t going to get better after all.

As with the first half, it was all Arsenal in the second as they tried to force an equaliser but when West Brom did manage to get forward, the Gunners’ defence rocked like a drunk weeble and we couldn’t even blame it all on Mathieu Debuchy.

Joel Campbell, brought on in place of Kieran Gibbs, was presented with a glorious chance to pull his side level only to skew his effort well wide to the visible anger of Arsene on the touchline. When he leaves Arsenal, and he will leave sooner rather than later, that miss will be the one you can point to and say that’s when his Arsenal career ended.

Arsenal continued to dominate but it always felt like they were just one brain fart away from losing a third as they tried to break down the bus Tony Pulis had wheeled out to try and see out the game. Quite how they didn’t when the ball hit the bar, bounced down on to the line and then the rebound was headed into the arms of Petr Cech is anyone’s guess. The flag also went up, but it was a reminder of how close Arsenal were to truly blowing their lines again when the top of the table awaited them.

Sensing that Arsenal wouldn’t be able to do it themselves, a combination of Chris Brunt holding Alexis Sanchez in the box and Mark Clattenburg actually seeing it, meant Santi Cazorla was handed a chance to level from the spot. Taking a short run up, the midfielder, who hasn’t scored since February, slipped John Terry-style and the ball blazed over.

It felt like we should all just call it a day.

On the day, Arsenal weren’t that bad but, as usual, a few lapses in defence combined with being wasteful in front of goal, cost Arsenal dearly. Arsene Wenger will likely come under pressure for such a poor result, but on the day it was the players who let him down.

It’s now his job to pick them back up.