Yaya Sanogo completed a first-half hat-trick on the stroke of half time to leave Arsenal 4-0 up at the break in their pre-season friendly against Benfica.

The home side wanted a penalty just a couple of minutes into the match when Eliseu brought down Joel Campbell in the box, but Lee Mason was not interested in the Arsenal appeal.

The Portuguese side looked dangerous on the attack as Nicolas Gaitan played his way into the box before unleashing a powerful strike, only for his finish to be kept out by the crossbar.

Arsenal were soon back in control though, with Tomas Rosicky firing just wide before Campbell and Sanogo also missed the target as the hosts piled the pressure on Benfica.

Sanogo made amends for his earlier miss in the 25th minute, as Aaron Ramsey made a run down the right flank before crossing in for Sanogo to convert from close range.

Campbell doubled the Gunners' advantage with six minutes until the break, volleying in from the back post following a Hector Bellerin cross.

There was still time for more from the hosts though, as Sanogo fired in twice more in the space of two minutes to complete his hat-trick, tapping in from a Ramsey delivery before being set up by Kieran Gibbs for his third moments later.