A 35-year-old British tourist was in the capital's Attiko Hospital in critical condition on Friday following a brawl with a fellow Briton in the party resort of Laganas on the Ionian island of Zakynthos on Thursday night.
According to witnesses, the man had been drinking at a bar in Lagana when, for reasons that remain unclear, two other patrons, also Britons, started threatening and pushing him.
The altercation continued in the street outside the bar where one of the two men reportedly punched the victim, who fell and struck his head on the ground, sustaining serious injuries.
The two men fled the scene but were found later with the help of an amateur video of the incident recorded by a passerby.
The man, who had been on Zaknythos with his family for a wedding, was first transferred to a local hospital where medics ordered him to be airlifted to the capital for specialist attention.
The two alleged assailants were to face a prosecutor on charges of aggravated assault.