Chelsea 6-0 Arsenal
Chelsea destroyed the celebrations for Arsene Wenger's 1,000th match in charge of Arsenal with a devastating 6-0 win at Stamford Bridge on Saturday, the Blues' biggest-ever victory over their North London rivals.
Goals from Samuel Eto'o and Andre Schurrle inside the opening seven minutes put Jose Mourinho's Premier League leaders on course for victory.
Then a remarkable refereeing error in the 15th minute gave Eden Hazard the chance to add a third from the penalty spot.
Alex Oxlade-Chamberlain clearly handled a Hazard effort at goal, but match official Andre Marriner brandished the red card at Kieran Gibbs instead. Despite the winger's confession to being the guilty party, Gibbs remained off the field.
Further woe was to follow for Wenger when Oscar added a fourth goal three minutes before the break after great work by Fernando Torres, who had replaced the injured Eto'o earlier in the game.
Oscar added a second goal in the 66th minute before Chelsea substitute Mohamed Salah scored his first goal for the club five minutes later.
While the headlines might be dominated by the refereeing error, there was little to disguise the poor display of the Gunners, whose Premier League title hopes lie in tatters.
But it was another clinical performance for Mourinho and Chelsea in their relentless pursuit of the championship.
Mourinho was quoted by the official Chelsea Twitter feed, @chelseafc, as saying:
There were 10 amazing minutes and with that you can win, and I am so happy with the approach. We came to kill.
After that first 10 minutes, the job was easy. We pressed them high and well and attacked the space very quickly.
Every match left is difficult. Manchester City and Liverpool have everything in their hands and only we have Champions League games.
Mourinho opted to play David Luiz and Schurrle in midfield in the absence of the suspended Willian and Ramires.
Blues' captain John Terry made his 400th Premier League start for the Stamford Bridge club.
Wenger kept the same team which defeated Tottenham at White Hart Lane last weekend.
Laurent Koscielny almost gifted Chelsea an early chance, but Wojciech Szczesny was off his line swiftly to deny Eto'o from a Schurrle cross.
Petr Cech needed to be alert at the other end to deny Olivier Giroud, but the deadlock was broken seconds later.
Schurrle broke free from the halfway line before laying the ball off to Eto'o on the right of the Arsenal area.
The striker cut inside Oxlade-Chamberlain before sending a curling left-footed shot beyond Szczesny in the fifth minute.
Two minutes later, the Blues doubled their lead through Schurrle. Nemanja Matic took advantage of a mistake to move forward before playing the ball to the German, who rifled past Szczesny.
In the ninth minute, though, Eto'o limped out of the game with what appeared to be a hamstring injury, and Fernando Torres came on.
Things went from bad to worse for the Gunners in the 15th minute in one of the most surreal moments ever in English football.
A Hazard shot was handled by Oxlade-Chamberlain. The offence took a few seconds to be adjudged as a penalty, but referee Marriner pointed to the spot.
However, the match official, bizarrely, sent Gibbs off when it was clearly Oxlade-Chamberlain who had handled the ball.
The fact that Hazard made it 3-0 from the penalty seemed inconsequential as a result.
Oxlade-Chamberlain appeared to inform Marriner that he was the guilty party, but it was Gibbs who left the field.
Luiz robbed Oxlade-Chamberlain in the 30th minute and moved forward at pace before firing a left-foot drive goalwards. The ball clipped Schurrle, but Szczesny produced a fine stop to prevent a fourth goal.
In the 42nd minute, Chelsea added a fourth through Oscar. Torres broke down the right channel after clever play from Schurrle, and played a low ball into the six-yard area for the Brazilian to slot home from close range.
Matic then tried his luck from the distance, but the shoulder of Koscielny blocked his effort.
Wenger made two changes for the second half with Oxlade-Chamberlain and Koscielny coming off for Mathieu Flamini and Carl Jenkinson.
A great run from Torres almost saw the Spain international add a fifth, but Szczesny saved well and then produced another block to deny Luiz.
Santi Cazorla was unlucky to see his 61st-minute effort flash across the goal as Chelsea appeared to be free-wheeling with their four-goal cushion.
Oscar saw his clipped effort touched over the crossbar by Szczesny after more good work by Torres on the right side.
Olivier Giroud launched a long-range strike in the 65th minute, but Cech never looked troubled.
Then a minute later, Oscar added his second of the game. A wayward pass from Tomas Rosicky was collected by the Brazilian, and his drive from the edge of the area beat Szczesny, although the Arsenal goalkeeper should have done better. Oscar was immediately switched by Mourinho for Mohamed Salah.
Salah's first significant contribution came in the 71st minute as he added a sixth for Chelsea. A lofted ball from Matic found the former Basel winger, who chased through to fire past Szczesny.
Arsenal had improved significantly in the second period, but the damage had long since been done.
The Gunners now have three days in which to prepare themselves for the league visit of Swansea City, as they seek to restore their battered title hopes.
Chelsea, though, have a full week in which to prepare for the trip to Crystal Palace, where they will hope to maintain their lead at the top of the table.
Selected player grades
Andre Schurrle: A+
An inspired switch by Mourinho to bring Schurrle into the starting XI. The Germany international was involved in everything throughout the game and deserved his moment in the spotlight.
Alex Oxlade-Chamberlain: C
The fact he remained on the pitch after his handball was remarkable, but his performance less so during a torrid opening 45 minutes for the Gunners. His replacement at half-time came as little surprise.
Fernando Torres: A-
Might not have started the game, but was a constant menace to Arsenal after replacing Samuel Eto'o early in the match.
Chelsea are next in action next Saturday when they make the short trip to South West London for the game against Crystal Palace.
Arsenal entertain Swansea City at the Emirates Stadium on Tuesday night in the Premier League.
Arsene Wenger was quoted on the club's official website as saying:
It was a nightmare and I take full responsibility for it. What is important is to give a response on Tuesday night and that is it.
The players are deeply disappointed as we all are. I think let us prepare for the next game
The referee made a mistake because he missed the identity of the player. He has not seen what happened at all. He gave a corner. Maybe it was a penalty. But it was not Gibbs.