Damage multipliers don't apply to base power -- they apply to the amount of damage dealt after the bulk of that has already been calculated. In practice, this doesn't count for much except some rounding, but it's worth mentioning seeing as this question is specifically concerned with when different multipliers are applied.
That's not to mention the answer is still not entirely clear about which one applies first (as much as that doesn't actually matter to OP, afaik).