By Greg Stobart at Stamford Bridge
As the praise poured down on Arsene Wenger in the build-up to this game, nobody could possibly have predicted that his 1000th game in charge of the Gunners would turn into such a disaster.
Or at least, no-one except Jose Mourinho.
Lukewarm in his praise of Wenger pre-match, the Chelsea manager rammed home his famous ‘specialist in failure’ jibe towards the Frenchman here with a result that made a mockery of Arsenal’s title aspirations.
It was an unforgivable decision from the referee and his assistants, a case of mistaken identity that will probably ensure he is watching Premier League action from his front room next week.
But no amount of incompetent refereeing could mask this pathetic Arsenal display.
Wenger’s players got it all wrong, but the Arsenal manager will have to accept the greatest share of the blame.
The Gunners fell straight into the trap set for them by Mourinho. With no defensive midfielder in the Arsenal starting line-up - Mathieu Flamini was named on the bench - Chelsea were able to rip through them on the counter-attack.
Wenger clearly failed to learn the lessons from previous big defeats away at Manchester City and Liverpool this season, when his side were blitzed early on, completely overrun and crumbled mentally and defensively.
Wenger may be a managerial legend, but on the evidence of the 11 matches and zero victories against Mourinho, he does not belong in the elite when it comes to building a squad and preparing a team.
Chelsea, for their part, registered their biggest Premier League win under Mourinho and scored six past their London rivals for the first time ever.
With seven games to play, Mourinho is the perfect man to steer Chelsea to the title, the kind of manager who would never oversee a nine-year trophyless period.
It was a game in which all of Arsenal’s flaws were exposed.
The last week has seen people hark back to the great Arsenal sides under Wenger, including their great midfielders like Patrick Vieira and Emmanuel Petit.
What Arsenal would do for some of that physicality in central midfield now, even some of the old nastiness.
Chelsea bullied Arsenal and stormed through the Gunners' limp midfield to expose a defence that played with a crazily high line.
At 5-0 down and with 10 men, Mohamed Salah was given almost half of the pitch to run into to complete the scoring. It was a goal that summed up both a shocking lack of defensive cohesion and total absence of tactical nous.
Moments change games and Arsenal’s need for a top class centre forward was again exposed when Olivier Giroud failed to generate enough power on a great early chance with the score goalless.
Two minutes later, Mikel Arteta lost possession in central midfield, Chelsea attacked swiftly and Andre Schurrle finished.
The Blues continued to fly forward and then Oxlade-Chamberlain conceded the penalty. The midfielder appeared to tell Marriner that he had sent off the wrong man but nevertheless Gibbs walked. And Hazard scored.
“We came to kill and in 10 minutes we destroyed them,” said Mourinho. “My analysis of the game is about that great 10 minutes.”
Oscar scored twice to take the score to five before substitute Salah ran in behind Arsenal’s crazy high line to slide home the sixth.
By that time, most of the 3,000 Arsenal supporters - superb throughout in their support of the visitors - were filing out of Stamford Bridge.
Many of them will, quite understandably, worship Wenger and be thankful for what he has achieved in the past. But once again he has been taught a lesson by Mourinho.