I was watching Tim Burton's Batman again and there's a scene in the bell tower where Batman gets his clock cleaned (pun intended). Up until then, Batman handled Joker's goons with ease. In fact, one of them tries to attack Batman and falls through the floor. Other guys had swords and are dispatched in seconds. But the final goon in the bell tower kicks Batman's butt, and pretty bad too, until he is killed in kind of a cheap shot.
What are some other example's of a hero/protagonist unexpectedly gets their butt kicked in a way that took you back a bit.