Arsenal went into the game looking to halt a run of four straight losses in all competitions and they faced a tough task on paper against an AC side reborn under Gennaro Gattuso.
The game got off to a fast start and looked set to live up to its billing as both Henrikh Mkhitaryan and Patrick Cutrone fired into the side-netting in the opening 10 minutes.
With just 15 minutes gone though it was the English side that took the lead. The hosts surrendered possession inside their own half and Mesut Ozil switch the ball out to Mkhitaryan out on the left with a fine first-time pass. The Armenian sized up his man before cutting inside Davide Calabria and powering an effort goalwards, with his strike taking a deflection off Leonardo Bonucci before sailing past Gianluigi Donnarumma in the home goal to give him his first goal in an Arsenal shirt.
8 March 2018
A brief lack of communication between Shkodran Mustafi and David Ospina threatened to hand Milan a route back into the game as the goalkeeper clattered his own defender when coming to punch a cross, but fortunately Giacomo Bonaventura could only volley the loose ball wide.
As the half wore on Arsenal started to look more and more dangerous Calum Chambers - playing in place of the injured Hector Bellerin - forced Donnarumma into a smart save with a strike from the edge of the box, before the Italy international had to be at his best to keep out Danny Welbeck’s low effort.
Four minutes were added on at the end of the first half and Arsenal made them count. Just minutes after Mkhitaryan had hit the bar following a similar move to the one that opened the scoring, the ‘Gunners’ doubled their lead.
Mesut Ozil was once again the architect slipping the perfect ball through for Aaron Ramsey to round Donnarumma and tap home from two yards to send Arsenal in two goals to the good at the break.
8 March 2018
That lead almost became three just four minutes after the restart as Welbeck looked to seize on Franck Kessie’s lazy ball back towards his own goal but the England man could only watch as Donnarumma’s clearance hit him and bounced inches wide.
From there on in it was all Milan. Bonaventura was on a one-man mission to get on the scoresheet as he took aim from all angles, but when a presentable chance fell to him he fluffed his lines.
With 52 minutes gone Calabria picked out the midfielder with a low cross but he could only fire over from the penalty spot under very little pressure.
Arsenal were content to defend at this point, aware that they had already put themselves in a very strong position in the tie.
Ricardo Rodriguez saw a volley drop well wide as the hosts continued to look for a way back into the game, but in truth they never looked like doing so.
Ospina was forced into one important late intervention as he raced off his line to clear the ball away from substitute Nikola Kalinic as he looked to be one-on-one, but other than that the Colombian was relatively untroubled as Milan’s main threat came from long-range strikes.
Arsenal now take two away goals and a clean sheet back to the Emirates ahead of next week's second leg, something which surely makes them favourites to progress to the quarter-finals.