The Gunners were at a low ebb heading to Italy after poor performances and damaging losses had seen the pressure cranked up on manager Arsene Wenger.

This was supposed to be another tough challenge for a beleaguered Arsenal at San Siro but instead they outclassed an admittedly poor Milan side as Henrikh Mkhitaryan and Aaron Ramsey struck in the first half to seal a comfortable 2-0 win in the first leg of this last-16 tie.

Mkhitaryan shone in the Europa League for Manchester United last season and topped that off by scoring in the final as the Red Devils saw off Ajax.

Wenger would love a similar run in this competition as all hopes of returning to the Champions League through the Premier League have all-but ended as Arsenal sit 13 points off the top four.

This was a massive night for both Wenger and his side and, for the first time in a considerable while, they answered some of the recent questions asked of their quality, commitment and togetherness.

It was not perfect and Milan had chances but the Rossoneri had not conceded in their last six games and had lost just one of their previous 20 European matches at the Giuseppe Meazza.

Gennaro Gattuso's side were inches away from taking the lead in just the second minute as Giacomo Bonaventura slid in at the back post but could not make contact with a deflected cross as the hosts forced the issue in the opening exchanges.

Arsenal also looked to make early in-roads and, although some of their pass selections - short and easy - showed that confidence is lacking, one smart move ended with Mkhitaryan firing into the side-netting.

But it would be the visitors who took the lead when the impressive Mkhitaryan cut inside from Mesut Ozil's pass before beating Gianluigi Donnarumma with a strike which deflected in off Milan skipper Leonardo Bonucci.

The home fans started to show their restlessness as Milan's players struggled to impose themselves on the contest, Calum Chambers forcing a decent save out of Donnarumma with a well-struck effort before Danny Welbeck passed up a glorious chance to add a second.

Welbeck did better moments later as Arsenal broke forward following a wasted Milan free-kick, switching play to Mkhitaryan who this time could only clip the top of the crossbar with his shot.

Arsenal would eventually, and deservedly, add to their lead before half-time to make their dominance pay, Ramsey showing superb composure to control Ozil's slide-rule pass and round Donnarumma to tuck home.

Welbeck again failed to convert when in behind before Bonaventura blazed over from inside the box as Milan went in search of a response.

Some mistakes crept into Arsenal's game, not helped when Sead Kolasinac limped off to be replaced by Ainsley Maitland-Niles.

But Milan never really looked good enough to threaten David Ospina's clean sheet, Suso firing well wide before Franck Kessie was challenged well by Laurent Koscielny as he looked to get a shot away.

There were no late moments of drama for Arsenal who saw the game out in a professional manner, something Wenger will be calling for in the return leg at the Emirates Stadium next Thursday.

- PA