The Frenchman struck twice to add to an earlier thunderbolt from the German before Cazorla and Walcott goals added gloss to the scoreline, despite initially falling behind
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 strike to seal an emphatic win.
The Gunners started brightly as they looked to get their slick passing game going from an early stage but 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 the Hammers landed a sucker blow.
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.
It appeared to wake Arsenal up again as they started zipping the ball around with more purpose, an equaliser would come quicker than anyone in the Emirates crowd could have anticipated.
Little trouble appeared on for the Hammers' rearguard when Wilshere clipped a delicate chip into the path of Podolski 25 yards from goal, but the German had other ideas as he unleashed a piledriver which flew past a stunned Jussi Jaaskelainen and hauled the North London outfit back on level terms.
They were looking to get the searing pace of Walcott in behind each time but West Ham held out well with a scrambled Podolski effort from Kieran Gibbs' cutback the closest Arsenal came to taking the lead prior to the interval.
West Ham were content to absorb pressure and hit their hosts on the counter attack, and it so nearly worked as Carlton Cole peeled off his marker and attempted a delicate chip over the onrushing Szczesny, but thankfully for Wenger and his side, Aaron Ramsey heroically cleared off the line albeit by also crashing into team-mate Thomas Vermaelen.
You sensed it would be the Gunners who would up the ante in the second half but they couldn't have dreamt what would happen so soon into the second period, as four goals in a blistering 11 minute spell saw the home side fly clear of the visitors.
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 the move which 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 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 and was treated on the pitch with various players looking concerned at what had happened.
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 that West Ham could only carry on with ten men against the rampant Gunners having made all of their three 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.