VIDEOS:
Let's take this to its peak!
Goku refuses to give up in his fight against Hit because even though he's outmatched, it wouldn't be fair to give up before he has given everything he has, no matter how risky. Hit, meanwhile, allows Goku to power up in defiance of his superior exactly because he sees an opportunity for improvement in Goku. Both are instances of this trope.
Example of:
Spirited Competitor