A 38-year-old man who was attacked outside a public house in a seaside town later died in hospital.
Jason Lee Craig Peers was assaulted outside the Dolphin Pub in Holdenhurst Road, Bournemouth, on Sunday.
A 29-year-old man, held in connection with the incident, has now been arrested on suspicion of murder.
Dorset Police said the victim, who lives in the area, died at the Royal Bournemouth Hospital. Police are appealing for witnesses.
A post-mortem examination is due to take place later.