Thanks to Glamdring for mini bio:

Ormung was lunarian (a race of folks that lived in the moon) that was more powerful than Superman. He became more powerful for exposure to our Sun turned him into a living star. He hit Superman with a punch that literally almost broke his jaw. Superman managed to out think Ormung who created a planet in their fight by trying to hit Superman with asteroids that eventually combined till they formed a world. Superman managed to lure Ormung near the Sun which its gravity Ormung had difficulty escaping.