Arsenal 3 Manchester Utd 0

Alexis Sanchez struck a first-half double at Emirates Stadium as Arsenal brushed United aside and leapfrogged them into second place.

Sanchez – who had netted a hat-trick in the Gunners’ previous Premier league outing at Leicester – grabbed two more to stun United, with Mesut Ozil also on target as the home side raced into a 3-0 lead within the first 20 minutes.

It was the perfect response to Arsenal’s European setback in midweek and lifted them above United on goal difference, just two points behind league leaders Manchester City.

Arsenal looked positive from the first whistle and stunned their visitors with their opening salvo as they swept into a two-goal lead inside seven minutes.

Aaron Ramsey took advantage of a square and static United defence to release Ozil, whose low cross to the near post was casually flicked home by Sanchez.

And the visitors were still trying to regroup when the Gunners doubled their lead – Ozil piercing the back line with a pass for Theo Walcott before collecting the return ball and drilling it past David de Gea.

The third Arsenal goal arrived in the 20th minute as Ramsey and Walcott combined to find Sanchez, who cut inside Matteo Darmian, shrugged off Chris Smalling and belted a 25-yarder into the top corner.

And the damage could have been even worse for the shell-shocked Red Devils, with Santi Cazorla arrowing a volley just wide and Walcott also off target.

Ramsey should certainly have added his name to the scoresheet 10 minutes before half-time, running behind Ashley Young to meet an exquisite Sanchez cross, but sidefooting wide with just de Gea to beat.

Yet the home side were indebted to the recalled Petr Cech for maintaining their three-goal lead just before half-time, denying Anthony Martial with his legs after the teenager had spun Per Mertesacker.

Cech was tested again soon after the break, moving across to save Young’s drive from just outside the box and then diving to turn a similar effort from Rooney behind.

United continued to threaten a reduction of the deficit and Cech had to smother a half-chance for Bastian Schweinsteiger before Juan Mata – a player with a penchant for scoring against Arsenal – curled one wide.

The home side created few openings in the second half, although Nacho Monreal set up Ozil with one that probably deserved better than a tame attempt straight at de Gea.

The outcome was the same when Alex Oxlade-Chamberlain scampered clear to tee up fellow substitute Olivier Giroud – and was unlucky to see his own chipped attempt rebound off the crossbar in injury time.

Arsenal: Cech; Bellerin, Mertesacker, Gabriel, Monreal; Coquelin, Cazorla; Ramsey, Ozil (Oxlade-Chamberlain 75), Sanchez (Gibbs 81); Walcott (Giroud 75).