The victim is believed to have suffered a concussion as a result of punches to the head.
States of Jersey Police are appealing for witnesses or information on an alleged assault which took place on Monday, 28 July at 9.15 pm, in the area of the Maupertuis pumping station in St Clement.
The victim is believed to have suffered a concussion as a result of punches to the head.
A man is alleged to have punched another man in an unprovoked attack.
Both individuals are in their mid-40s. The suspect is believed to have been walking a small white dog.
Police are particularly keen to speak to a female driver of a Ford Focus who intervened and encouraged the males to separate.

Details announced of free childcare for two and three year olds
18-year-olds to have access to Jersey social housing
CI ferry operators to work together to improve inter-islands travel
'Show up and play' football games to tackle festive loneliness
New website helps children and families navigate the digital world
More time in Jersey for French day-trippers
Rapist jailed more than two decades after his crime
Jersey Airport to see 20,000 passengers in the run up to Christmas