Chelsea suffered a big blow in the title race when they lost to Aston Villa last week, with Ramires and Willian picking up suspensions in the process, but they were at their absolute best on Saturday. Arsenal conceded early, then crumbled completely at Stamford Bridge, marking Arsene Wenger's 1000th game in English football with an embarrassing 6-0 defeat.
Perhaps even more so than for the score, this game will be remembered for a case of mistaken identity by referee Andre Marriner. He failed to spot a handball off the line by Alex Oxlade-Chamberlain in the 15th minute, but after consulting with his assistant, he decided to give a penalty and show a red card. Except, hilariously, he showed it to Kieran Gibbs. Oxlade-Chamberlain tried to tell Marriner that it was him who had handballed, but the referee had none of it.
Whether or not it was preferable for Arsenal to still have Gibbs on the pitch instead of Oxlade-Chamberlain, the game was already over by the time that mistake by Marriner had any effect at all. Eden Hazard's penalty after that handball was not the game's first goal, but its third.
Arsenal actually started brighter in the opening minutes and nearly took the lead, with Petr Cech coming up with an excellent save on Olivier Giroud from just inside the box. But just one minute later, the script flipped completely, with Samuel Eto'o curling a perfect shot to the back post from the edge of the penalty area to put Chelsea ahead 1-0. Just 90 seconds after that, Andre Schürrle matched him with a shot to the same spot, from the same spot, stunning Arsenal.
Eto'o had to come off injured in the 10th minute, but his absence didn't hinder Chelsea, who went 3-0 ahead after Hazard's penalty. Just before halftime, the Blues found a fourth, with Eto'o's replacement setting up Oscar with a square ball that the Brazilian was able to smash into the back of the net.
That goal ended a 10-game goalless streak for Oscar, and he wasn't done there. He completed a brace in the 66th minute, hitting a drive from outside the box that took a bounce in front of Wojciech Szczesny, fooling him and preventing him from making a save. Mohamed Salah was subbed in for Oscar immediately afterwards and went on to score a goal of his own just five minutes later, after beating Arsenal's offside trap running onto a long ball by Cesar Azpilicueta.
And with that, Arsenal have a very serious uphill battle to get back into the title race. They're not completely out of it by virtue of having a game in hand on Chelsea, but they're now seven points back of the Blues, and could find themselves the same number behind Manchester City in short order.
Chelsea: Cech, Azpilicueta, Terry, Cahill, Ivanovic, David Luiz (Mikel 72'), Matic, Hazard, Oscar (Salah 67'), Schürrle, Eto'o (Torres 10')
Goals: Eto'o (5'), Schürrle (7'), Hazard (penalty 17'), Oscar (42', 66'), Salah (71')
Arsenal: Szczesny, Gibbs (red 15'), Koscielny (Jenkinson 46'), Mertesacker, Sagna, Arteta, Oxlade-Chamberlain (Flamini 46'), Podolski (Vermaelen 24'), Rosicky, Cazorla, Giroud