>>32333574First-stage Digimon and first-stage Pokemon tend to have comparable power. Champion-level Digimon and many fully-evolved Pokemon are roughly comparable too, though the balance definitely favors Digimon. Some pseudos
mostly just Tyranitar, if five regions of Pokedex entries are to be believed and the stronger Megas might be able to take on the less impressive Ultimate level digimon.
As far as I know (which, regarding Digimon, admittedly isn't a lot), there are no non-legendary Pokemon capable of standing up to a Mega level Digimon.
Looking at VS Battles Wiki, it looks like it depends entirely on the Pokemon and Digimon in question. Tyranitar being a good match for most Champion and low-level Ultimate Digimon seems to hold up though, so I'll say that's my answer.
