The victim was left lying on the floor of the Green Island Rugby Football clubrooms as a function wound down shortly after the bar was closed at midnight.
Police and paramedics were alerted about 12.20am and rushed to the Neill St clubrooms.
On arrival, emergency services found the man in a critical condition, though a police spokeswoman said he was later reported as being in a serious but stable condition in Dunedin Hospital.
A 23-year-old Dunedin man is due to appear in the Dunedin District Court tomorrow on a charge of assault.
Officers remained at the clubrooms yesterday morning but had completed their inquiries at the scene and left by noon.
Green Island Rugby Football Club president Craig Anderson confirmed the man charged was a club member who played in the Premier 2 grade.
He and the rest of the club were upset up the incident and expressed their sympathies for the victim, who remained in hospital.
Mr Anderson said the accused was a Dunedin local, whose parents he knew.
"I know the guy's parents very well and they're devastated, obviously."
The victim was not a member of the rugby club, but he understood the man, who appeared to be aged in his mid to late 20s, was associated with a nearby cricket club.
Any action taken by the club against the accused would happen after the court process, he said.
- Dunedin police (03) 471-4800, Crimestoppers 0800-555-111.
