He was taken to the Eastbourne District General Hospital but doctors were unable to save his life.
Detective Inspector Wendy Burton, from the Surrey and Sussex Major Crime Team, said yesterday: "It's so tremendously sad that this man has died, an absolute tragedy. Our heartfelt condolences go to his family.
"We are doing all we can to learn about what happened that night, the circumstances that led to this attack and now his untimely death.
"I would appeal to anyone who was in the area last night and who may have any information, however small, to come forward."
Supt Trevor Botting, East Sussex Division command, said: "The community is shocked by this horrific incident. We will be talking to residents during the coming days to reassure them and keep them informed about the investigation."