Police forensics officers were seen scouring the pavement for evidence between the White Horse pub and Man’s Chinese Takeaway in Butts Road following the incident, which is believed to have taken place at around 12.30am.
Hampshire Police confirmed later on Sunday that a 22-year-old man from Alresford suffered an injury to his eye and was taken to Southampton General Hospital, where he was discharged the same day.
The pavement, opposite the M&S food hall, was cordoned off overnight up until around mid-morning.
Investigations are ongoing and anyone with any information is asked to contact Hampshire Police on 101, quoting reference 44180157349.