Four second half goals from Arsenal stunned West Ham at the Emirates Stadium, as Lukas Podolski's finest performance as a Gunner erased memories of consecutive defeats for the north Londonders.
Podolski, a summer acquisition from Cologne, drew Arsenal level after Jack Collison had given West Ham an early lead, before creating three more goals in ten crazy post-interval minutes.
Olivier Giroud scored from a Theo Walcott corner immediately after the break, then Podolski played a part in the following three as Santi Cazorla, Walcott and Giroud all breached the stunned West Ham defence.
The Hammers, for their part, had looked dangerous in the first-half - despite being defensive minded - and scored the opener early after managing to camp out in the Arsenal box for the first time.
Two chances in succession resulted in corners, the second of which floated to Collison on the edge of the box, who cushioned on his knee and thrashed a left footed half volley through a crowd of players and into the net. It was the Welshman's first goal since scoring against Cardiff in the playoff semi-final and West Ham's first away from home since their last trip to north London, against Tottenham in November.
Only four minutes later and Arsenal were on terms. Podolski, clearly frustrated at the sky blue wall constructed in front of the area, cracked a shot from 25-yards with his left foot, which screamed past the outstretched glove of Jussi Jaaskelainen.
For all their possession, Arsenal could hardly muster a clear opportunity, although perhaps should have taken the lead but for Joey O'Brien's intervention from a Podolski shot.
The Hammers could have quite easily themselves ended the half in front, but Thomas Vermaelen this time cleared his lines after Carlton Cole had rounded Wojciech Szczesny.
Any hope West Ham had of keeping things tight after half-time were soon extinguished when Giroud poked in at the near post, before Cazorla rounded off a fine move six minutes later.
Giroud found Podolski with a delicate lob, before the German squared for Cazorla, who flicked between his legs into the unguarded net.
A two goal advantage became a three goal advantage one minute later when Podolski opened his legs from a Jack Wilshere through ball and slid across to Walcott who tapped in for his tenth goal of the season.
Podolski was not finished yet, however, who once again left Guy Demel floundering - on the day he signed a new West Ham contract - and this time provided Giroud with a simple chance to convert.
With the result gone for the visitors 12 minutes into the second-half, concern soon turned to young Dan Potts who was stretchered off after a lengthy delay with a particularly distressing looking injury. The teenager had been on the pitch for only ten minutes, and his exit left the Hammers a man short, having used their full compliment of substitutes.
Potts' injury resulted in 12 minutes of stoppage time and, although Mohamed Diame tried to affect the encounter on an apparent Arsenal audition, the scenes previous had sucked the life from proceedings.
Arsenal then are four points from the Premier League's top four after this, their game in hand, while West Ham sit in 12th - and how they would settle for that come May.