Anyone who watched the game for any length of time (or followed my live blog) could hardly believe the scoreline at the end of the game.
Arsenal dominated for almost 90 straight minutes, had about 72 percent of the ball (via Sky Sports) and took 26 shots, 12 of which were on target (via ESPN FC). Yet none of this added up to a single goal.
With this loss, the Gunners can all but rule out winning a trophy for the eighth straight year, and many will doubt their ability to even hold their own against German juggernauts Bayern Munich.
In the wake of one of Arsenal's most painful defeats of the season, let's look at five things we learned.