Pep Guardiola has warned his Bayern Munich team to learn from the "big lesson" that Manchester City taught them in tonight's 3-2 Champions League defeat at Eastlands.
Ten-man Bayern - who had Mehdi Benatia sent off after 20 minutes - looked on course to defy the odds after goals from Xabi Alonso and Robert Lewandowski cancelled out Sergio Aguero's first-half penalty.
However, Aguero struck twice in the final five minutes to seal his hat-trick and stun the German giants in the process on a dramatic night at the Etihad Stadium.
Bayern had already won Group E prior to kickoff, but the Spaniard says that a similar collapse in the knockout stages could have devastating effects on their title bid.
"Even though we lost, I am very proud of my team," Guardiola told UEFA.com.
"We played with ten men for much of the game, despite that we continued to dominate possession and play an aggressive game.
"But that sort of thing happens in the Champions League, perhaps tonight is a big lesson for us. This is a group game, if it happens in the last 16 onwards then you are out of the competition."
The Bavarians will conclude the group stages by hosting CSKA Moscow - who sit fourth in the table, but level on points with second-placed City - at the Allianz Arena next month.