How did Doctor Octopus survive even one punch from Spiderman in Spiderman 2?

In Spiderman 2, Spiderman punches Doctor Octopus in the face a lot.

Since Doctor Octopus is just a normal man with robotic arms attached to his back / spine, how is he able to endure all this super powered face punishment?

I suppose many of the people Spiderman punches in the face aren't super powered, so he's probably holding back most of the time.

But specifically for the movie, was this issue ever addressed?