A 29-year-old man was smashed in the head with a glass bottle when a large brawl between a group of men and women erupted during a party at a hotel in the Bronx early Thursday, authorities said.

The violence broke out at around 6:25 a.m. inside a room at the Ramada on Baychester Avenue in Co-op City, police said.

During the 25-minute melee, involving about 10 people, the man was hit on the side of his face with the bottle, causing a severely bleeding laceration, cops said.

The fight then spilled out onto the street on Baychester Avenue between Darrow Place and Donizetti Place, police said.

Emergency responders rushed the man to Jacobi Medical Center. His condition was not immediately known.

No arrests have been made.