A 65-year-old man is in hospital with serious head injuries and a 32-year-old man is being questioned by police, following an incident at a Doncaster working men's club.
The incident took place at Skellow Working Men's Club around 11pm last night.
A South Yorkshire Police spokesman said: "At this time the victim is still in hospital with serious but not life threatening injuries.
"One 32 year old man is in custody being questioned by detectives.
"Can we ask for anyone who witnessed the incident or has any information to assist with the inquiry to get in touch with Police via 101, quoting incident number 1132 of January 22, 2017 or anonymously through crimestoppers."
Following the incident a police cordon was in place around the club up until this afternoon, while police carried out inquiries into the incident.