We obtained the police report -- the reality star was busted in Westmoreland County, Pennsylvania after cops say she crashed her vehicle into a tree. The wreck, which happened on June 27, left a telephone pole hanging over Christi's car.

Cops say she exhibited all the classic DUI signs ... bloodshot and glassy eyes, slurred speech and the officer on the scene reported the smell of alcohol on Christi's breath.

According to the docs, Christi admitted to having 2 glasses of wine before getting behind the wheel ... and was asked to take a preliminary breath test, which came back positive.

She was also asked to do standard field sobriety tests ... which officers say showed she was impaired and couldn't safely operate a vehicle.