In a competition that Unai Emery loves, the Spaniard could only guide his Arsenal side to a home draw (1-1) against Sporting, their second draw in a row after Liverpool in the Premier League last time out.
It was the hosts that took the game to their opponents, and they were lucky to still be on level terms before half-time.
The only blemish on a great opening half from the Gunners, apart from a lack of goals, was an injury to Danny Welbeck which saw him go off after half an hour.
Pierre-Emerick Aubameyang came closest to a goal all night when his shot cannoned back off of the post a minute after the break, and from there on it was a backs-against-the-wall performance from the Portuguese side.
Jeremy Mathieu was sent off late on for the visitors, and he will miss the next game.