Olivier Giroud and Mesut Ozil fired Arsenal to a home win over Bayern Munich in the Champions League, to ensure they remain in the competition.
Olympiakos winning against Dinamo Zagreb meant that a defeat would have seen the Gunners eliminated, having lost their first two games in the competition.
Former Newcastle striker and Match of the Day pundit Alan Shearer took to Twitter after the 2-0 victory - and raised a crucial point regarding the first two games in the competition.
Shearer asked once again why manager Arsene Wenger decided to bench goalkeeper Petr Cech for the club's first two games.
Wenger controversially picked David Ospina against Dinamo Zagreb and then Olympiakos, with the Colombian letting him down with individual errors.
Ospina is currently sidelined with injury meaning Wenger could not be tempted into making a repeat of his earlier selection. 21-year-old stopper Matt Macey was on the bench, while Cech's clean sheet saw him win the battle with opposite number Manuel Neuer in Bayern's goal who was beaten twice.