Black spot on Phal amabilis leaf

[lepetitmartien]

Looks a lot like Acidovorax so bacterial, but of slow, it may be a fungus. Personal guess is Acidovorax.

You did the best removing it. Keep us informed if it comes again, then there will be retaliation to kill it nicely if possible.

[Orquiadicto]

I will, I promise.
I cut off well beyond the limit of the mark (more than double the size of the spot itself) so I hope I cut off all the affected tissue.