Credit: YouTube

On Monday night (Sept 14), one of the the hottest parties of the entire week — by far — was the V Magazine hosted after party for the Marc Jacobs show, with a performance by none other than the iconic performer Lady Gaga.

All the stars came out to show love and watch the madness unfold!

Troubled actresses Mischa Barton and Lindsay Lohan, stylist to the stars Rachel Zoe, Ciara, rocker Courtney Love, Toni Braxton, and even Janet Jackson stopped by to party with MJ…..the other one! Ha!

Watch Gaga’s acoustic performance of Poker Face and Just Dance after the jump! Or just click here!

Other stories you might love:

1. No Wonder Marc Jacob’s Afterparty Was At Capacity Before The Party Started!
2. Lady Gaga And Marc Jacobs ACE Up In NYC!
3. I:Spy Lorenzo Martone At Marc by Marc Jacobs
4. VIDEOS: Lady Gaga Performs At amfAR Gala Honoring Natasha Richardson!
5. Posh Jacobs: Victoria Beckham and Marc Jacobs Do Paris!