Godzilla vs. Megalon (1973)
Godzilla vs. Megalon is a 1973 Japanese science fiction kaiju film produced by Toho. Directed and co-written by Jun Fukuda with special effects by Teruyoshi Nakano, the film starred Katsuhiko Sasaki, Hiroyuki Kawase, Yutaka Hayashi, and American actor Robert Dunham. It was the thirteenth film in the Godzilla franchise. Heavily influenced by the tokusatsu superhero TV shows of the time, the film had Godzilla essentially acting as a costar to a huge robotic superhero character called Jet Jaguar.
More at Wikipedia.