A Success man is due to face court after allegedly striking a Secret Harbour man in the head with a bottle at the Ravenswood Hotel, during the Screaming Jets concert.
Pinjarra Police senior sergeant Ian Francis said the incident happened after the pair had an altercation in the bathroom on Friday, about 10.45pm.
The 39-year-old victim received medical treatment for cuts to his head at the Peel Health Campus.
The 41-year-old offender was arrested nearby and charged with unlawful wounding.
He due to appear in the Mandurah Magistrates Court on September 28.