A Crawley man has been arrested on suspicion of GBH and assault following a fight in Burgess Hill on Saturday (January 31).
Police said a fight broke out between two men between 3am and 3.30am in the Waitrose car park.
One man, a 30-year-old from Haywards Heath, sustained a serious injury to his ear and hand.
The Crawley man, 28, has been bailed until March 28 while investigations continue.
Detective constable Becki Buckley said: “If you were in the area in the early hours of Saturday morning and think you may have witnessed the incident please contact us on firstname.lastname@example.org or call 101, quoting serial 0188 of 31/01.
“You can also call the independent charity Crimestoppers on 0800 555 111.”