Arsenal advanced into the last 16 of this season’s UEFA Champions League with a stunning 3-0 win against Olympiacos in what was a hostile atmosphere.

Going into the clash, the Gunners needed to win by a margin of two goals, and they did that and more. Olivier Giroud was the star of the show as he bagged his first hat-trick for the club.

But what did we learn in Greece tonight? Let’s take a look at five things.