Police said the brawl occurred outside 1st Stop Café around 22:00 on Sunday, the evening of the World Cup final.
Two men – both believed to have known each other – were involved.
One of them, a 19-year-old, was taken to the hospital by Police with “minor injuries”. The other was reported to have fled the scene.
Pictured: The assault was reported to have occurred in the area of Cheapside, St. Helier.
Those with information should contact Police on 612612 or make an anonymous report on the Crimestoppers website by clicking here.