Hammer blow hands Wenger a reality Cech
And so this proved to be the reality Cech. The Cech mate, if you like. The jokes, the social media chat, the internet 'gifs', bar-room riffs and sense of shock will reverberate.
Arsenal 0 West Ham 2
Schadenfreude is not the latest signing from Bavaria but the only way to describe the unforgiving glee with which rival supporters reacted to Petr Cech's calamitous Premier League debut for Arsenal.
Calamitous? Cech did not throw the ball into the net, or let a soft shot trickle through his legs but such is the rarified level at which this world-class goalkeeper works that he has to share a huge amount of responsibility for the goals as West Ham United achieved a remarkable and assured victory.
The positives for West Ham were bountiful with their new manager, Slaven Bilic, putting down a well-deserved marker, with his key signing Dimitri Payet proving to be a key player and Reece Oxford - the club's youngest-ever player (at 16 years and 237 days), the seventh youngest to play in the Premier League - enjoying a freakishly outstanding debut.
Cech had been hailed as the signing of the summer, an incredible coup given that he was allowed to leave Chelsea and join their title rivals. The missing piece of a league-winning jigsaw, even. It may eventually prove to be the case and he is certainly one of the world's outstanding goalkeepers. But not on this evidence. He did not earn points.
He lost them. And Arsenal need more than Cech. Arsenal wanted to make a statement, but this was not the one they hoped to release. Maddeningly for their fans, this was one of those performances they produce now and again where they appeared to simply think they could turn up and win, perhaps fooled by West Ham's Europa League exit and recent serial failure against Arsenal.
There was a lack of drive, impetus and, dare it be said, leadership from the home side. A lack of urgency - until the blind panic of a cavalry-charge after falling two goals behind with manager Arsene Wenger throwing on Theo Walcott and Alexis Sanchez.
Wenger looked crushed, and there were the inevitable boos. The Arsenal manager talked of how there was collective responsibility in the West Ham goals.
Poor organisation - and terrible tracking from Nacho Monreal - was a vital part of the first and slow reactions were crucial to the second. But Wenger knows the focus will be firmly on his new goalkeeper.
Cech will bounce back. Arsenal will too. But Wenger ruefully remarked that away to Crystal Palace and home to Liverpool - their next two fixtures - did not represent a soft landing into the season.
Arsenal must be markedly better. Markedly better in defence - and this was their most experienced, with a back five all aged over 30 - and in midfield where they lacked that bit of grit and the over-reliance on Francis Coquelin was exposed.
Santi Cazorla played the first half out wide and Mesut Ozil's contribution was fitful. Olivier Giroud was in 'failing to strike a bovine posterior with a banjo' mood.
Arsenal struck the crossbar, with Aaron Ramsey's shot deflecting off Aaron Cresswell and over Adrian to clip the frame of the goal, Alex Oxlade-Chamberlain volleyed narrowly over and there was a frantic charge at the end with the goalkeeper saving smartly from Cazorla and Sanchez. But there was precious little else.
Neither did Arsenal have the comfort of arguing that West Ham had come, parked the bus and hit them on the counter-attack. No, there was far more structure and belief and positivity in Bilic's side - and a bit of ruggedness with three yellow cards in the first half - as they shared possession.
And there was that quality, also, that Payet is expected to bring. At 28, the French midfielder is in his prime and arrived in the Premier League from Marseille for a big fee that could rise to £14m and he immediately looked the part. He was clever, strong and game-smart.
Payet can also take a free-kick. He flighted the ball superbly, before half-time, for Cheikhou Kouyate to attack the space permitted by the Arsenal defence.
They had, inexplicably, pushed up too far with Monreal detailed to track Kouyate - which he failed to do. Cech spotted the danger but was too slow off his line and could only flap at the ball as the header powered past him.
For the second Cech also appeared ponderous. Oxlade-Chamberlain surrendered possession and it ran to Mauro Zarate, who was given an unforgivable amount of time and space to adjust himself and drive a low shot goalwards. Cech had shifted his weight to his left foot as the ball came through on his right but was unable to adjust and, once more, seemed slow to cover.
Again the ball was in the net. Even so, there was more than half an hour for Arsenal to rescue the encounter. Plenty of time for a team of their ability and Bilic knew that as he hopped from foot to foot in the technical area and crouched low, willing the clock to run down.
But the response was not good enough and a famous West Ham victory was achieved.
Cech slowly trudged across the turf at the end. This was not the debut he dreamed of. It was not what Arsenal expected either. (© Daily Telegraph, London)