I forgot a few of Godzilla's early TV appearances. They happened in Ultra Q (as the monster Gomess, which was a redressed '64 suit) and this one on the sequel series, Ultraman, which is a redressed '65 suit. I first read about this appearance in either Marvel's "Monsters of the Movies" magazine (written by Don Glut) or in Don's excellent "Classic Movie Monsters" which was possibly the first book to get almost all the information about Godzilla and Gamera right. I sure read it a lot at the time. I thanked him for writing so well about Japanese movies at a time when most critics wrote them off as garbage.
It's a good episode, though seen with today's sensibilities Ultraman is kind of cruel to Kira, who really didn't do anything to anyone during the episode. It's also a kind of violent episode, with blood coming out of Kira's mouth during the battle.
Oddly some Godzilla fans get bent about "Godzilla" losing this fight.