Police were called to Relish on East Laith Gate in Doncaster at around 9.15pm on Friday November 28 following reports of an assault.
A 50-year-old man was taken to hospital with facial injuries. He remains there under observation but his injuries are now not thought to be serious.
A 23-year-old man was arrested on suspicion of assault. He remains in police custody.
Witnesses or anyone with information is asked to call South Yorkshire Police on 101 quoting incident number 1119 of 28 November.