Premier League: Arsenal 5 West Ham 1

Arsenal have stunned West Ham with a second-half blitz, moving to within four points of fourth-placed Spurs with a 5-1 win at Emirates Stadium.

An Olivier Giroud brace, accompanied by further strikes from Lukas Podolski, Santi Cazorla and Theo Walcott boosted the Gunners’ chances of qualifying for the Champions League for a 16th successive season, as they recovered from Jack Collison’s stunning opener to seal an emphatic win on Wednesday.

The Gunners started brightly as they looked to get their slick passing game going from an early stage but they had to be wary of the physical threat posed up front by the visitors, who created the first real opening, but Ricardo Vaz Te’s downward header sailed wide.

Arsene Wenger’s men responded as a trademark Jack Wilshere burst from midfield took him past his man before slipping in Walcott with a sumptuous pass, but the winger could not get a shot away as Joey O’Brien tracked back in time.

It all appeared to be going the way of the Gunners in the opening stages before West Ham landed a sucker blow 18 minutes in.

A series of corners eventually led to Giroud’s weak header finding the unmarked Collison who rammed home an unstoppable left-foot strike beyond the despairing dive of Wojciech Szczesny on 18 minutes.

It appeared to wake Arsenal up again as they started zipping the ball around with more purpose, with an equaliser coming just four minutes later.

Wilshere clipped a delicate chip into the path of Podolski 25 yards from goal, and the German unleashed a piledriver which flew past a stunned Jussi Jaaskelainen and hauled the North London outfit back on level terms.

The sides headed to the interval at 1-1, but whatever Wenger said at half-time sparked Arsenal into some serious form and four goals in the first 12 minutes of the half blew the game apart.

First, Walcott’s whipped corner was met by Giroud, who turned home on the volley at the near post before the Frenchman was involved in a move that saw Podolski square for Cazorla to slide home a neat finish despite being under heavy pressure from O’Brien.

If the Gunners faithful thought that was good, they hadn’t seen anything yet, as Walcott got in on the act by smashing past Jaaskelainen from Podolski’s cross after a lightning counter-attack.

Giroud added to his earlier finish with a swept finish from yet another Podolski cross to make it 5-1 as Arsenal threatened to run riot.

It was damage limitations for Sam Allardyce, who responded by throwing on young Dan Potts to deal with the pace of Walcott and Alou Diarra for some defensive nous.

Potts would only last a few minutes on the pitch as he went down following an aerial duel with Bacary Sagna.

He was treated on the pitch for more than 10 minutes for a head knock and was eventually stretchered off and taken to hospital.

Wenger had also chosen to make the most of his substitutions as he looked to take the sting out of the game as well as resting some of his first-team stars ahead of a testing FA Cup trip to Brighton at the weekend.

The injury to Potts meant West Ham had to finish the match with 10 men, having made all three of their substitutions and 12 minutes of stoppage time was subsequently awarded for the time it took to take the defender from the pitch.

Allardyce’s side managed to hold out for the remaining minutes with Arsenal strolling through the gears as they secured a valuable three points in their quest for Champions League football next season.