King Kong vs. Godzilla (1962)

Mr. Tako, head of Pacific Pharmaceuticals, is frustrated with the television shows his company is sponsoring and wants something to boost his ratings. When Doctor Makino tells Tako about a giant monster he discovered on the small Pharaoh Island, Tako believes that it would be a brilliant idea "...with a punch" to use the monster to gain publicity. Tako immediately sends two men, Sakurai and Kinsaburo, to find and bring back the monster from Faro.
Meanwhile, the American submarine Seahawk gets caught in an iceberg. Unfortunately, this is the same iceberg that Godzilla was trapped in by the JSDF seven years earlier in 1955 in the movie Godzilla Raids Again. As an American rescue helicopter circles the iceberg, Godzilla breaks out and heads towards a nearby Japanese Arctic base. The base, of course, is ineffective against Godzilla. Godzilla's appearance is all over the press and makes Tako angry. As Tako is complaining about Godzilla's media hype to his employees, one of them exclaims "And... there's a movie too!"
Meanwhile on Pharaoh Island, a giant octopus attacks the village. King Kong finally makes his appearance and defeats the monster. Kong then drinks some red berry juice and falls asleep. Sakurai and Kinsaburo place Kong on a large raft and begin to transport him back to Japan. Back at Pacific Pharmaceuticals, Tako is excited because Kong is now all over the press instead of Godzilla. As Tako is out of the room, one of the employees ask which is stronger between King Kong and Godzilla. Another employee responds "Stupid, it's not a wrestling match!" Tako walks back in the room and exclaims "I'll buy that idea!"

Mr. Tako arrives on the ship transporting Kong, but unfortunately, the monster then wakes up and breaks free from the raft. As Kong meets up with Godzilla in a valley, Tako, Sakurai, and Kinsaburo have difficulty avoiding the JSDF to watch the fight. Eventually they find a spot. Kong throws some large rocks at Godzilla, but Godzilla shoots his atomic ray at Kong, so King Kong retreats.

The JSDF constantly try and stop both Kong and Godzilla but are mostly ineffective. They set up some power lines filled with a million volts of electricity (compare that to the 300,000 volts Godzilla went through in the original movie). The electricity is too much for Godzilla, but it seems to make King Kong stronger. Kong attacks Tokyo and holds a woman from a train, named Fumiko, in his hand. The JSDF explode capsules full of the berry juice from Pharaoh's scent and knock out King Kong and rescue Fumiko. Tako approved of this plan because he "...didn't want anything bad to happen to Kong." The JSDF then decide to transport Kong via balloons to Godzilla, in hope that they will fight each other to their deaths.
The next morning, Kong meets up with Godzilla and the two begin to fight. Kong manages to push Godzilla back on Mt.Fuji and Godzilla's Atomic breath becomes more of a nuisance than anything to Kong, however the battle turns in Godzilla's favor when Kong slips and knocks his head on some rocks. Godzilla eventually knocks Kong unconscious after attacking him multiple times, but a thunder storm arrives and refreshes King Kong, giving him the power of an electric grasp. The battle then turns immediately in Kong's favor who proceeds to easily overpower and throw around Godzilla, suplexing him and punching him into the ground. Eventually he sticks a tree down Godzilla's throat, causing Godzilla to light it on fire. Kong continues pushing Godzilla back, tearing down Atami Castle in the process, and eventually plunging alongside him into the sea. After an earthquake, only King Kong resurfaces and begins to slowly swim back home to Pharaoh. As Kong swims home onlookers aren't sure if Godzilla survived the fight, but speculate that it was possible.