Against the odds: 3 reasons why Arsenal advanced to Round of 16

The name has changed, but the Europa League remains the competition Arsenal will avoid with pride following a decisive victory over Olympiacos to maintain the club's 16-year run of group-stage success.

Arsenal's past failures were forgiven when the final whistle sounded and Olivier Giroud's hat trick propelled the visitors to a 3-0 victory and secure the team's progress into the Round of 16. It was a result worthy of advancing after the Gunners dropped the home fixture 3-2 to the Greek side at the Emirates Stadium in September.

Here's three reasons why Arsenal advanced to the knockout stage:

Overcoming past demons

It's hard to argue with the ever-present doubt in the mind of Arsenal supporters when Giroud opened the scoring inside the game's first 30 minutes. The goal provided a scoreline just shy of the required result to see the Premier League side through.

Sure, it was an ideal position to be in considering more than half the game was still to be played, but the early advantage was a familiar circumstance that historically ended in disappointment for Arsenal.

Even though the incidents that continue to haunt those associated with the English side occurred in the Round of 16, the nervous ticks persisted Wednesday. During three of Arsenal's last four tournament-deciding matches, the club found itself in need of a certain goal total, only to come up agonizingly short against the likes of AS Monaco (2014-15), Bayern Munich (2012-13), and AC Milan (2011-12).

Crucial Bayern Munich victory

With elimination appearing to be an inevitability after two losses and a home date with a European powerhouse, an inspiring Arsenal performance against Bayern Munich was rewarded with two late goals to help temporarily erase the sour taste of a winless start and revive hopes of advancing.

Much like Wednesday's triumph over Olympiacos, Giroud played an integral role in the contest when his opening goal stunned Bayern and was eventually followed by a Mesut Ozil tally in a match that ended the German giant's unbeaten run in all competitions.

The job was far from over as a return fixture against the German champions in Munich awaited - which saw Bayern come away with a dominating 5-1 win - but Arsenal's victory provided the north London outfit with a crucial first three points that ended up being the difference between continuing to participate on Europe's biggest stage and the club's first Europa League appearance since 2000.

Steady hand in goal

Few incidents this season can match the outrage after David Ospina's dreadful performance that saw Arsenal drop the first leg to Olympiacos at the Emirates.

Pundits and supporters were up in arms with manager Arsene Wenger's decision to play the Colombian over Petr Cech - the team's only acquisition during the summer. Ospina's abysmal display culminated when he, somehow, fumbled a corner-kick and allowed the ball to bounce into his own net to give the Greeks the lead before going on to register a win.

Since then, it's been all Cech, as the former Chelsea netminder provided a steady hand in goal that helped guide Arsenal record three wins in its final Champions League matches.