Alexis stole the show as Westham were brutalized by Arsenal

Alexis Sanchez stole the show with a hat-trick as Arsenal moved second in the table and heaped more pressure on Slaven Bilic's West Ham with a comprehensive 5-1 victory at the London Stadium.

Having set up Mesut Ozil for Arsenal's opener on 24 minutes, Sanchez capped a stunning individual display with three goals in 15 second-half minutes.

Andy Carroll's marked his long awaited return to the West Ham first-team with a goal nine minutes from time but Alex Oxlade-Chamberlain's response a minute later ensured it was mere consolation for the hosts, who remain a point above the relegation zone and without a league win since mid-October.

For Arsenal, a first victory at their London rivals' new home sees them extend their unbeaten run in the league to 13 games and remain three points off leaders Chelsea.

With first-team regulars Michail Antonio and Aaron Cresswell out injured, West Ham could ill afford another defensive injury against an Arsenal side they've not beaten on home turf in the top-flight in over a decade.

But, with just five minutes on the clock, that was exactly what happened as James Collins was forced off.

Alvaro Arbeloa replaced the Welshman but the Spaniard appeared off-guard as the Gunners exposed his lack of preparation.

Nacho Monreal twice got the better of his compatriot on 13 minutes but crucial interventions from Angelo Ogbonna and Winston Reid prevented Arsenal from taking the lead.

A subdued West Ham took 19 minutes to fashion their first chance, Petr Cech alert at his near post to tip Manuel Lanzini's effort out for a corner.

But just as the hosts looked to be finding their rhythm in attack, Arsenal pounced on a defensive lapse to take a deserved lead.

After Francis Coquelin had blocked Ogbonna's sloppy pass, Sanchez skipped past Reid and through on goal he unselfishly squared for Ozil to notch his eighth goal of the season.

It was no more than the Gunners deserved, and they should have been out of sight by half-time but a combination of Darren Randolph and Reid were on hand to thwart Sanchez on 36 minutes.

       .          Mesut Ozil celebrates with Alexis Sanchez
The Hammers sought refuge at the interval, and looked to strike fear into the Arsenal camp by sending Carroll out to warm up.

Bilic, however, opted not to bring Carroll on immediately, a decision which almost paid dividends as the impressive Ashley Fletcher flashed a shot wide on 55 minutes.

Arsenal soon regained control though, and only a perfectly-timed Ogbonna block and a fine double save from Randolph kept West Ham in the game.

But there was only so much the hosts could withstand as Sanchez's stunning solo effort - spinning away from Arthur Masuaku before beating Randolph - on 72 minutes doubled the Gunners' advantage.

His instinctive first-time finish eight minutes later made it three and marked the start of a frantic final 10 minutes which would see four goals scored.

Within three minutes, Carroll, making his first appearance since mid-August, headed home from close range after Dimitri Payet's sensational free-kick had cannoned off the frame of the Arsenal goal. 

West Ham's faint hopes of a comeback, though, were extinguished a minute later when Oxlade-Chamberlain's fizzing drive restored Arsenal's three-goal lead.

It was then left for Sanchez to complete his hat-trick with a audacious chipped finish three minutes from time as Arsenal remained firmly in the title race.