Arsenal came from behind to beat West Ham 3-1 at Upton Park in a feisty London derby. A cameo substitute appearance from unsettled winger Theo Walcott turned the game in the Gunners's favour as he claimed a goal and an assist. The win lifts Arsenal to fifth in the Premier League table, just two points behind fourth-placed West Brom.
Arsenal started the match on the front foot and carved out the first meaningful chance in the sixth minute when Santi Cazorla found space on the edge of the box but saw his right-footed drive deflected behind for a corner.
It was only 15 minutes later when Mohamed Diame gave the Hammers the lead with a magnificent curling strike after nut-megging Aaron Ramsey to score from the tightest of angles and send the bubble-blowing contingent of Upton Park into raptures. He was then booked for an over-exuberant celebration. West Ham then found themselves in the driving seat, but could not convert a flurry of well-placed set-pieces into clear-cut opportunities.
Shortly before half-time came the moment that all Arsenal fans have been waiting for since the start of the season. Olivier Giroud scored his first goal for Arsenal since his big money summer transfer from Montpellier after sliding in to meet a low Lukas Podolski cross at the near post.
West Ham were surprisingly the team that put Arsenal under pressure at the start of the second half with a flurry of corners before Andy Carroll appeared to miss a great chance in the 54th minute after Nolan had seen his effort blocked, but the former Bolton midfielder had already been flagged offside.
The home side came out at the start of the second half by far the stronger and immediately piled the pressure on the Gunners. Their first decent effort of the second 45 was when a long throw from Demel was flicked on by Carroll, only for club record signing Matt Jarvis to smash his shot into the stands.
Arsenal hit the Hammers on the counter-attack in the 65th minute, just minutes after Wenger had introduced Walcott and the substitute accidentally blocked a Cazorla shot. But he back-heeled the ball to Giroud who did well to get a shot away on the slide from a tight angle, only for his effort to find the side-netting.
In his first start since his home debut against Fulham Andy Carroll missed a glorious opportunity to give the home side the lead. He leaped above Vito Mannone, and with the goal gaping, drifted his header wide of the far post. Kevin Nolan was the next West Ham man to spurn a great chance when, after getting in behind the Arsenal defence, tried to cut inside and lost the ball when he should have shot.
Those missed chances seemed to push Arsenal into action and they were screaming for a penalty when Aaron Ramsey went down on the edge of the area, but Phil Dowd waved away the appeals.
After Lukas Podolski had seen a low drive stopped by Jussi Jaaskelainen, Olivier Giroud sprung Walcott clear with an inch-perfect through-ball which the England winger duly converted as he slotted low to give Arsenal a precious lead with just 13 minutes remaining.
Sam Allardyce's team had a great chance to respond quickly, as less than two minutes after Walcott's strike the ball fell to Nolan, but he again wasted the chance and shot high over the cross-bar.
The game was basically over in the 83rd minute as Walcott cut inside and laid the ball off to Santi Cazorla who thumped in a stunning strike into the far top corner to give the Gunners a two-goal cushion going into the final minutes.
Giroud missed one last one-on-one in stoppage time, but it didn't matter as Arsenal comfortably held on to seal a crucial three points.