A 37-year-old man needed hospital treatment for a fractured eye socket after being attacked while walking home in Brackley.
It happened along Hill Street at about 1.15am on Sunday when a silver Citroen Picasso drew up alongside him. Two men got out and assaulted him, also causing cuts.
Both offenders were white and taller than 5ft 7in. One was wearing a light-coloured jacket.
Anyone who witnessed the incident should call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.