Lisa Vanderpump received a very special guest on Wednesday night at PUMP Lounge.

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As she continues to filming the sixth season of The Real Housewives of Beverly Hills, and the fourth season of Vanderpump Rules, Vanderpump was visited by pop star Lady Gaga, who shared a photo of the two of them on her Instagram page.

A photo posted by The Countess (@ladygaga) on Aug 12, 2015 at 11:11pm PDT

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In addition to sharing Lady Gaga's Instagram post on Twitter, Vanderpump also shared a re-tweet from a fan, who posted a series of photos of Vanderpump and the singer coming out of her West Hollywood, California restaurant.

During Lady Gaga's PUMP visit, she surprised her fellow guests with an unexpected performance.

“Nobody knew Gaga was there until she started singing ‘La Vie En Rose’ a cappella. The whole restaurant stopped and turned to watch her perform the one song. It was magical,” a source told Page Six on Thursday.

Then, on the way out, Lady Gaga, who was "dressed in a floor-length black-and-red velvet kimono and black high-heeled mules," tripped and fell into the street as she walked to her waiting 1960s Lincoln Continental convertible.

“Lisa was concerned when she went down, but she helped her up and off she went,” said the source. “She handled it like a pro.”

Tags: lisa vanderpump Lady Gaga Bravo Reality TV vanderpump rules The Real Housewives of Beverly Hills