When Lex Luthor challenged Superman to a fair fight, man-to-man, on even terms, without his super-powers to help him, the Man of Steel accepted the challenge. As Superman would have no powers on a planet like Krypton that revolved around a red sun, he built a spaceship to take the pair of them to such a world. It was agreed that if Superman won the fight, Luthor would return to Earth with him and serve out his prison sentence. But if Luthor won, he would leave Superman on that planet and return alone. Landing on a dying desert world, the two fought a boxing match, which resulted in Superman winning.
Believing Superman to have perished in a sandstorm which struck not long afterwards, Luthor came across a city where the people had once been a great scientific race, but presumably following a great war eons ago which wiped out their civilization, had returned to stone age life due to no longer having any understanding of science or technology. Luthor revived the planet's science, but the people's greatest problem was a shortage of water; the only source was a fountain in the city, which Luthor had discovered would soon fail. Although Luthor constructed robots to dig deep underground to find water, he was unsuccessful.
When Superman arrived in the city, the pair continued their fight in a ancient arena, this time each using sets of ancient inventions against each other. Eventually, the two ended up fighting man-to-man once more, during which Luthor suddenly weakened, giving himself up and vowing to go back to Earth, with Superman, to prison. As the spaceship left the solar system with the red sun and entered one with a yellow orb, Luthor – who had promised to get the people water – persuaded Superman (who had now regained his super-powers) to throw masses of frozen water from an icy planet back to the desert world. This Superman did, at the same time activating Luthor's robots by his x-ray vision to build canals like those on Mars which would bring water all over the planet, and leave its people forever grateful to Luthor.
In prison on Earth. Luthor received a present from Superman: a photograph taken through a super-telescope in Superman's Fortress of Solitude, showing a great statue of Luthor on the one world where he was a hero.
The planet would later be named Lexor by its people.
- This version of Lexor, including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.