A dazzling Alexis Sanchez hat-trick fired Arsenal up to second in a 5-1 thumping of West Ham.
The Chilean striker made it five goals in his last two appearances to keep Arsene Wenger's side hot on the tail of Premier League leaders Chelsea.
The Gunners should have been out of sight at half-time but wasteful finishing saw them go into the break just one goal up after Mesut Ozil's tap in.
Already depleted by injuries, West Ham's evening started badly when defender James Collins hobbled off after just seven minutes.
They managed to keep it at 1-0 for a good portion of the game but couldn't find anything like a finish to the few chances they made, with Koscielny intercepting their best chance from a Lanzini cross.
Arsenal's second arrived in the 72nd minute when Sanchez burst into the penalty area, brushing off Arthur Masuaku and Ogbonna before drilling his shot across Randolph and into the net, and the Chilean added a third eight minutes later.
Andy Carroll emerged from the bench after three-and-a-half months out and pulled one back when he headed in the rebound after Payet's sumptuous free-kick hit the crossbar.
Arsenal restored their three-goal advantage moments later with Oxlade-Chamberlain rifling home from long range for his first Premier League goal since the opening day of the season.
Sanchez completed his sparkling treble in style, racing onto the Ox's pass and putting Randolph on his backside with a cute dummy before clipping home.