Arsenal 5 Benfica 1

Yaya Sanogo scored four times as rampant Arsenal thrashed Benfica on the opening day of the Emirates Cup.

The young striker completed a 19-minute hat-trick in the first half, with Joel Campbell also on target, and added his fourth goal of the afternoon before Nico Gaitan netted a consolation for Benfica.

Sanogo became the first Arsenal player to score four goals in a game since Andrey Arshavin at Liverpool five years ago – and the result puts the Gunners in a commanding position to win their own pre-season tournament for the first time since 2010.

Monaco, who drew 2-2 with Valencia in the first game of the tournament, will be the hosts’ second opponents on Sunday (kick-off 4.20pm).

The Portuguese champions were first to threaten as Maxi Pereira cut the ball back for Gaitan, who let fly with a first-time effort that clipped the crossbar.

But Arsenal gradually got on top, with Aaron Ramsey pulling the strings and setting up Campbell with a clever dink over the top, only for the ball to stick under the Costa Rican’s feet.

Sanogo should have opened the scoring soon afterwards when Hector Bellerin played a one-two with Campbell and crossed to the near post, but the ball bounced off the striker’s shins and wide.

However, the breakthrough arrived on 26 minutes – again from a break on the right as Ramsey, with a neat turn to leave Benito stranded, raced into the box and set up Sanogo for a tap-in.

At the other end, Damian Martinez was called into action with a low save to foil Eduardo Salvio – but that was Benfica’s final sniff of a recovery as the floodgates opened in the last four minutes of the first half.

Bellerin was the orchestrator of the Gunners’ second goal, playing a one-two with Sanogo and crossing for Campbell, who showed good technique as he met the ball with a precision left-foot volley into the far corner.

The visitors’ back line began to disintegrate and Campbell should have scored again, screwing wide after Ramsey had teed him up – but he made amends by squaring for Sanogo to make it 3-0 soon afterwards.

Incredibly, there was still time for the young Frenchman to complete his treble before the half-time interval as Kieran Gibbs whipped in a cross and Sanogo got between two defenders to nudge the ball over the line.

And there was no respite for Benfica after the break as, four minutes after the restart, Ramsey’s angled drive was parried by Moraes Artur and the rebound was gobbled up by Sanogo to make it 5-0.

The Gunners made a raft of substitutions on the hour mark and it seemed they were still adjusting when Benfica pulled a goal back, Bebe glancing on a throw-in for Gaitan to head home.

There was little response from either the player or crowd to that goal – something of a contrast to the exuberance that greeted the introduction of Alexis Sanchez 10 minutes later.

However, there were few opportunities for the £30m Chilean star to shine in the remainder of the game, with Bebe’s free-kick bringing a good save from Martinez and Pereira hitting the woodwork.

Arsenal might have added further gloss to the scoreline as Ignasi Miquel went close with a header and Francis Coquelin struck the post with a low drive in the closing seconds.

Arsenal: Martinez; Bellerin, Chambers, Monreal (Miquel 73), Gibbs; Ramsey (Wilshere 61), Flamini (Arteta 61); Campbell, Rosicky (Coquelin 61), Oxlade-Chamberlain (Cazorla 45); Sanogo (Sanchez 73).