They eventually lost 3-1, meaning Arsenal had an uphill task on their hands during Thursday's second leg at the Emirates stadium.
After celebrating his second goal in Arsenal's 3-0 win in the UEFA Europa League on Thursday night by putting on a special mask, African superstar Pierre-Emerick Aubameyang explained the reason for his new celebration.
But they put in a commanding performance as they won 3-0.
However, it was not forthcoming and with VAR not in operation in the Europa League unlike the more lucrative Champions League, Maitland-Niles's downward header from Aubameyang's cross was allowed to stand.
It doesn't seem like the fan has taken the defeat too well.
Since then though he has positioned the team in fourth spot in the Premier League with eight games of the season to go.
"It was very clearly an injustice, it was a manifest error", Stéphan said.
'I think it characterises us and it characterises this league at the moment as well that all six teams have got through to the quarter-finals, ' he added. "First of all, because it means we are in the final and I am happy with that", Sarri said. "So, for me, it will be very hard to play against them in Naples". Playing under pressure and growing up under pressure, each player, as a team, they feel hard moments to give us our best performance.
"But I think we can feel this competition like in the Premier League, to do a good way and create, with our supporters, a big atmosphere and a big feeling together to do this way in the Premier League and also here in the Europa League".