Ambulance staff were called to the scene inside the Gandhi Restaurant on Hollow Lane, South Hayling at around 1am.
A 65-year-old man was taken to the Queen Alexandra hospital in Cosham but died shortly before 10am on Saturday.
Three men aged, 32, 34 and 37 were arrested on suspicion of murder. The 34-year-old man has since been released but remains under investigation.
Anyone with information about the incident is asked to call the Major Crime Department at Fratton police station on 101 or call Crimestoppers anonymously on 0800 555 111.
Police would like to thank those who dined at the Gandhi Restaurant on Friday evening, 3 November who have already contacted us and are asking anyone else who did go there that evening but hasn’t been in touch to please do so as they may have vital information.