Bayern Munich 3-3 Arsenal ...... As you can see there was nothing to separate the two sides last time around. The eventual European Champions (Bayern) went through on AWAY goals aggregate, JUST!
Oh, and that was when Arsenal were very poor in defending last season, and no Ozil and Flamini in the side, and no revitalised Ramsey. The EPL league LEADERS are a different kettle of fish this season as their strong league position shows and a better side all round than the team Bayern edged on the away goal rules.
Yes, Bayern are the clear favourites to go through but favourites don't always win football matches as Galatasaray demonstrated in their win against Juve. Write Arsenal off at your peril, Rikki.