#2 A two goal deficit in the first leg left Napoli with a mountain to climb

Napoli left themselves with a lot of work to do as they hosted Arsenal at the San Paolo Stadium. Arsenal came into the second leg with a two goal advantage thanks to Aaron Ramsey's strike and an own goal from Koulibaly.
The hosts went into this game knowing well that an early goal was a must if they wanted to find a route back in the tie. Napoli enjoyed most of the possession early on and created decent chances, only to be denied by some lacklustre finishing and brilliant organisation by Arsenal's back five.
Napoli had a number of glorious chances in the first leg which fell to Insigne and Mertens. Had they converted those chances, it could have been a different game altogether. Arsenal, on the other hand made use of their chances and could have put the tie to bed in the first leg itself as Aubameyang and Lacazette missed sitters in the first leg.
The Italian outfit grew increasingly frustrated as they looked to cut down the deficit through an early goal, which also resulted in them losing composure in front of goal. Moreover, Lacazette's strike in the 36th minute saw them having to score four goals in the next 54 minutes against a well organised Arsenal side on the night.
Milik and Insigne missed some easy chances which they would have converted on some other day. Due to lack of composure and insipid finishing, Napoli found themselves in a difficult position of having to score four, which resulted in them committing mistakes and Arsenal exerting a stronghold on the tie.
A more phased display over the two legs from Ancelotti's side could have seen Napoli have a better chance to progress to the semis.