Hayden Panettiere Drunk and Frantic According to New Police Report

Hayden Panettiere answered the door to police last month in an apparent drunk and frantic state after her new beau got into an altercation with his dad ... according to cops.

TMZ has obtained a police report from the Greenville City Police Department in South Carolina regarding an incident that went down late last month between Hayden's beau Brian Hickerson, and his father David. Police responded to a call for assault and battery.

According to the docs, the responding officer saw what appeared to be Brian chasing his father through the house with a Gatorade bottle in his hand. The officer says Hayden rushed to open the door for him in a panic, and he immediately put Brian in cuffs to figure out what was happening.

The officer says Brian was uncooperative, refusing to give any personal info because of the potential negative impact the incident could have on Hayden. Hayden fessed up ... she and the father had been drinking before the altercation.

David had visible injuries on his face -- severe bruising and bleeding -- he said he had just fallen.

Our sources say Hayden denies having been drunk.