Arsenal struck back to clinch an important win from a difficult position after beating West Ham despite going behind in the second half to a Carlton Cole effort. Theo Walcott bagged a brace before Lukas Podolski added a third for the Gunners.
The only black mark for the visitors was an injury to Aaron Ramsey, although within the context of the game, the enforced substitution that resulted from his knock ended up having a big hand in the result.
After a fairly low-key start, Olivier Giroud had the first real chance of the game but mistimed his run, and failed to get a connection to Bacary Sagna's excellent cross. Mark Noble then almost made Arsenal pay by curling in a smart free-kick just afterwards at the other end, but Szczesny managed to claw the ball away from the top corner.
Santiago Cazorla almost scored a most unlikely opener afterwards, heading from all of 19 yards at the Hammers goal from a poorly-cleared corner, but Adrian managed to reposition himself to make the save. Arsenal were beginning to create chances, and Walcott missed a good chance after collecting Ramsey's pass, before Giroud hit an awful effort wide when presented with a good chance too.
Although Arsenal were dominant, they had occasionally been looking complacent at the back, and West Ham were more than doing enough to keep themselves in the game. Yet few would have predicted the sudden twist at the beginning of the second half, as Wojciech Szczesny fumbled Kevin Nolan's shot to present Carlton Cole with an easy chance to put the Hammers into a shock lead.
Arsenal now faced a huge test of their mentality and title credentials, but they almost blew it as it was the hosts who had the better of the game thereafter. Carlton Cole missed another good chance before Joey O'Brien spurned the opportunity to make it two by missing a real sitter, getting a free header for which he did not even have to leap twelve yards from goal, but guided his effort wide.
Carlton Cole had yet another opportunity to extend West Ham's lead when he picked up Matt Jarvis' superb cross which was misjudged by Szczesny, but the big man could only prod it wide. As was painfully obvious, the hosts would soon regret missing that flurry of chances, as Arsenal steeled themselves and began to look for a way back into the game, although did suffer a setback when Aaron Ramsey went off injured for Lukas Podolski. That seemed to be another disaster for the visitors, although it would go on to have a hugely influential effect on the result.
Theo Walcott was the man to level the scores and deal a terrible blow to West Ham's chances as he scored a slightly fortunate goal, cutting in and hitting a low effort which somehow found its way through the crowd of players and eluded the well-positioned but poorly-sighted Adrian to creep into the net.
The goal seemed to deflate the hosts, and it wasn't long at all before Walcott had another, heading in thanks to some terrible defending from West Ham and a wonderful cross from the substitute Podolski. Despite their earlier promise, the Hammers looked done, and it was no surprise at all to see the fourth goal of the day go to Arsenal again, with Podolski making the game safe by firing in from the edge of the area after collecting Giroud's lay-off.
West Ham were well-beaten and left it too late to muster any serious threat to Arsenal's goal, Joe Cole going closest in the dying minutes, but their quick collapse had long ago secured all three points for Arsenal. A satifying result for Arsene Wenger's men, who could very easily have lost further ground in the title race.
West Ham: Adrian; O'Brien (Demel 63'), Tomkins, Collins (Rat 38'), McCartney; Jarvis, Nolan (Taylor 75'), J Cole, Noble, Diame; C Cole.
Goals: C. Cole 46'
Arsenal: Szczesny, Sagna, Mertesacker, Vermaelen, Gibbs, Arteta, Ramsey (Podolski 65'), Cazorla, Ozil (Flamini 81'), Walcott, Giroud (Bendtner 85')
Goals: Walcott 68', 71', Podolski 78'.