Scary moment at Beyoncé and Jay-Z's pad this week ... cops say a man crashed his car into the front gate of their swanky New York estate ... and he left in handcuffs.

The 63-year-old motorist drove his car "at a high rate of speed up the driveway" of their East Hampton mansion and smashed through the gates ... according to the police report, obtained by TMZ.

Officers say the man didn't the brakes when he came up on the mechanical gates, allegedly causing "significant damage."

Cops say his car was impounded, he was placed under arrest, and was brought to Stoney Brook Hospital for pain.

Detective/Sergeant Jennifer Dunn -- one of the responding officers -- told Page Six the man seemed "confused," saying ... "He did not make any threats or mention names of the residents. It could just be chance he picked that house if he was having a medical issue."

She explained he'd previously stopped at a house down the road, looking for a woman who didn't live there.

The man was charged with felony criminal mischief and misdemeanor criminal trespass.

No word if Beyoncé and Jay were home.