The 54-year-old victim had been sent unconscious to Princess Margaret Hospital, following the reported brawl at the junction of Pei Ho Street and Apliu Street.
The 39-year-old man was also hurt, sustaining head injuries. He was treated at Caritas Medical Centre but remained conscious.
Police had arrested both men for fighting in a public space. But the 59-year-old died at 7.20 pm on Tuesday.
The manslaughter case will be mentioned at West Kowloon Magistrates’ Courts on Wednesday morning.
A post-mortem will also be held.