Lady Gaga -- DOWN SHE GOES!!! (VIDEO)

Lady Gaga enjoyed her trip to Lisa Vanderpump's West Hollywood restaurant ... maybe a little too much.

Gaga was leaving Pump Wednesday night with Vanderpump by her side, and she definitely looked a little worse for wear.

And wouldn't you know it ... when it came to getting into her car, Gaga couldn't quite muster up the dexterity it took to step off the curb ... and instead fell in the street like a ton of bricks.

But she shook it off like a champ (or just didn't feel anything) and got into the car on the second try.

By the way ... cool car.