I called this feat an outlier, and that wasn't far wrong. However, a more accurate assessment would be that it was misapplied:
It doesn't apply to Thor as he normally is, but rather to the latent inner power that, in rare occcasions, comes out when he needs it, which the story actively emphasizes when it talks about Thor's incoming birth. For instance,
here, it's stated that Thor's strength is such that he may destroy the world even before he is born.
This inner power, elsewhere, is referred to as Thor's life-force, his very essence,
which is also the source of the God Blast, and we already know that the God Blast consistently allows Thor to harm cosmic entities that are otherwise way above his paygrade.