This is just, eh.
I mean, even though the weak beating the strong is like, a common theme in toaru, this is just eh.
Like, she won by a sudden powerup instead of outwitting her opponent or something.
The powerup came out of nowhere and doesn't seems warranted.
And she never clashed her ideal and logic against her opponent and just "curbstomp" her way to a victory.
It's like, breaking all three rule of a good "david vs goliath" story.