VIDEO: Giroud, Campbell team up to help Arsenal reach the knockout stages

Once overlooked but now integral to Arsenal's aspirations, Costa Rican international Joel Campbell used a series a deft touches to take down a long ball before finding a streaking Olivier Giroud to double Arsenal's lead at Olympiacos in the 49th minute.

The French striker would complete his hat-trick later in the second stanza, putting the Gunners on the brink of completing their great escape from the group stage.