¿Esto suena natural? So that's why you are quiting. You(ve?) met your match.

No, this guy is more than my match. He's way beyond me.

@treyl
In practical terms, both past simple and present perfect can imply completion, it depends who's speaking and in what situation.

RIGHT NOW:
"What happened? Are you okay??"

North American: ...I think I broke my foot.
British: ...I think I've broken my foot.

(completed action/event)

North American: I ate lunch (already).
British: I've eaten lunch (already).

As a North American English speaker, I find past actions are logically completed actions too so that's why "I ate " is natural and I can emphasize completion by adding "already."

Otherwise, use of both forms is pretty consistent.

PAST:
"What happened to you last week?"

North American: I broke my foot.
British: I broke my foot.

(stating a fact)

PAST EXPERIENCE
"Have you ever broken a bone?"

North American: I've broken my foot four times.
British: I've broken my foot four times.