。
Got it!
Literal
Caught.
A one-word sentence: the past-tense verb 捕まえた alone, standing as an exclamation. Japanese happily drops subject, object, and everything else when the context supplies them — a fleeing target just caught, a solution just grasped, or a tagging game won. Context is the only thing distinguishing 'caught him!,' 'got it!,' and 'gotcha!' in the original.