The form book went out of the window at San Siro as Arsenal ran out 2-0 winners against Milan in the first leg of their Europa League round of 16 clash.
Henrikh Mkhitaryan and Aaron Ramsey got the decisive first-half goals for Arsene Wenger’s side, who entered the match having lost five of their last six in all competitions.
Despite long periods of pressure from the home side, they couldn’t break down a resilient Arsenal back line, meaning they have it all to do at the Emirates in a week’s time.
The Rossoneri could have taken the lead inside three minutes as a corner was cleared to Suso, who whipped in a teasing low cross that just evaded Giacomo Bonaventura at the far post.
Arsenal began to get themselves into the game, and had an opportunity not long after as Jack Wilshere dropped a pass back to Henrikh Mkhitaryan, who struck a first-time effort into the side netting.
Patrick Cutrone had his first chance up the other end as he was put through in the box by Hakan Calhanoglu, however the young Italian toe-poked his effort into the side netting too.
Calhanoglu was the centre of a key incident as he was given a run towards the box, and as he took the ball past David Ospina he jumped the keeper’s challenge but stayed on his feet, where a fall may have resulted in a penalty.
However, it was Arsenal who took the lead through Mkhitaryan, as the attacking midfielder cut in onto his right foot before his effort deflected off Bonucci and past a helpless Donnarumma.
Donnarumma was called into action twice more before the end of the first-half as Calum Chambers blasted an effort goalwards which the teenager was on hand to parry clear.
The second chance came as Danny Welbeck was played in behind; the England international sending a weak attempt at Gigio, who saved comfortably.
Mkhitaryan could have given the Gunners a two-goal lead in added time as Welbeck lead a break, but he skimmed the bar with his shot after cutting inside in a similar fashion.
Aaron Ramsey did double their advantage seconds before the whistle as he was played in behind, taking the ball around Donnarumma and slotting home despite accusing glances from the Milan defence.
Arsenal had the first chance of the second-half as Kessie shanked a ball back towards Donnarumma nearly stole in on; the ball eventually ricocheting for a goal kick.
Bonaventura should have done better moments later when a low cross from Calabria found him inside the area, but he couldn’t keep his hooked effort down.
Ricardo Rodriguez had a half-chance to reduce the deficit for the Rossoneri with just over 20 minutes left as a corner fell to his path, though he dragged his volley wide as time began to run out.
Bonaventura, who struggled to find his feet in the game, saw the ball find him at the far post from a corner, but his effort was well blocked as the visitors continued to be resolute in defence.
Ospina had to be alert as he rushed off his line inside the last ten minutes to deny Nikola Kalinic, who would have had an easy finish from a delicate through ball.