The man, originally from Africa, suffered from a knife wound and was seen lying near the Blanche streetcar (tram) stop near the intersection of Rue de Carouge and Rue Blanche, the Tribune de Genève reported online on Sunday, citing information it received.
The Tribune reported the man collapsed in front of numerous witnesses at around 11.30pm.
The person or persons who attacked the man have not been apprehended, the newspaper said.
Geneva police have confirmed the murder but are otherwise not commenting.
The force’s criminal division is in charge of the investigation, the Tribune said.
A witness told the newspaper that ambulance attendants stayed with the man who remained on the ground for about an hour.
The Tribune said it appeared the man died on the spot.
Witnesses said police cordoned off a section of the Rue de Carouge and inspected the pavement with flash lights until 1am on Sunday.
An elderly lady in the neighbourhood said she had heard about a fight in front of a café-restaurant at the Place des Augustins, three blocks away from where the man was found, the Tribune de Genève said.
However, the restaurant owner told the newspaper that “nothing special” occurred outside the restaurant of Saturday night.